diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 0623d08d..1c5801a1 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -29,6 +29,7 @@ class calendar extends rcube_plugin
   const FREEBUSY_UNKNOWN = 0;
   const FREEBUSY_FREE = 1;
   const FREEBUSY_BUSY = 2;
+  const FREEBUSY_TENTATIVE = 3;
   const FREEBUSY_OOF = 4;
   
   public $task = '?(?!login|logout).*';
@@ -51,6 +52,8 @@ class calendar extends rcube_plugin
     'calendar_timeslots'    => 2,
     'calendar_first_day'    => 1,
     'calendar_first_hour'   => 6,
+    'calendar_work_start'   => 6,
+    'calendar_work_end'     => 18,
   );
 
   private $default_categories = array(
@@ -116,7 +119,7 @@ class calendar extends rcube_plugin
       $this->register_action('freebusy-status', array($this, 'freebusy_status'));
       $this->register_action('freebusy-times', array($this, 'freebusy_times'));
       $this->register_action('randomdata', array($this, 'generate_randomdata'));
-      $this->register_action('print',array($this,'print_view'));
+      $this->register_action('print', array($this,'print_view'));
 
       // remove undo information...
       if ($undo = $_SESSION['calendar_event_undo']) {
@@ -508,6 +511,7 @@ class calendar extends rcube_plugin
             . ' ' . html::a(array('onclick' => sprintf("%s.http_request('event', 'action=undo', %s.display_message('', 'loading'))",
               JS_OBJECT_NAME, JS_OBJECT_NAME)), rcube_label('undo'));
           $this->rc->output->show_message($msg, 'confirmation', null, true, $undo_time);
+          $got_msg = true;
         }
         else if ($success) {
           $this->rc->output->show_message('calendar.successremoval', 'confirmation');
@@ -597,10 +601,11 @@ class calendar extends rcube_plugin
     $end = get_input_value('end', RCUBE_INPUT_GET);
     if (!$start) $start = mktime(0, 0, 0, 1, date('n'), date('Y')-1);
     if (!$end) $end = mktime(0, 0, 0, 31, 12, date('Y')+10);
-    $events = $this->driver->load_events($start, $end, null, get_input_value('source', RCUBE_INPUT_GET), 0);
+	$calendar_name = get_input_value('source', RCUBE_INPUT_GET);
+    $events = $this->driver->load_events($start, $end, null, $calendar_name, 0);
    
     header("Content-Type: text/calendar");
-    header("Content-Disposition: inline; filename=calendar.ics");
+    header("Content-Disposition: inline; filename=".$calendar_name);
     
     echo $this->ical->export($events);
     exit;
@@ -624,6 +629,8 @@ class calendar extends rcube_plugin
     $settings['timeslots'] = (int)$this->rc->config->get('calendar_timeslots', $this->defaults['calendar_timeslots']);
     $settings['first_day'] = (int)$this->rc->config->get('calendar_first_day', $this->defaults['calendar_first_day']);
     $settings['first_hour'] = (int)$this->rc->config->get('calendar_first_hour', $this->defaults['calendar_first_hour']);
+    $settings['work_start'] = (int)$this->rc->config->get('calendar_work_start', $this->defaults['calendar_work_start']);
+    $settings['work_end'] = (int)$this->rc->config->get('calendar_work_end', $this->defaults['calendar_work_end']);
     $settings['timezone'] = $this->timezone;
 
     // localization
@@ -1204,6 +1211,7 @@ class calendar extends rcube_plugin
     if (!$start) $start = time();
     if (!$end) $end = $start + 3600;
     
+    $fbtypemap = array(calendar::FREEBUSY_FREE => 'FREE', calendar::FREEBUSY_BUSY => 'BUSY', calendar::FREEBUSY_TENTATIVE => 'TENTATIVE', calendar::FREEBUSY_OOF => 'OUT-OF-OFFICE');
     $status = 'UNKNOWN';
     
     // if the backend has free-busy information
@@ -1212,9 +1220,9 @@ class calendar extends rcube_plugin
       $status = 'FREE';
       
       foreach ($fblist as $slot) {
-        list($from, $to) = $slot;
+        list($from, $to, $type) = $slot;
         if ($from <= $end && $to > $start) {
-          $status = 'BUSY';
+          $status = $type && $fbtypemap[$type] ? $fbtypemap[$type] : 'BUSY';
           break;
         }
       }
@@ -1254,9 +1262,9 @@ class calendar extends rcube_plugin
       if (is_array($fblist)) {
         $status = self::FREEBUSY_FREE;
         foreach ($fblist as $slot) {
-          list($from, $to) = $slot;
+          list($from, $to, $type) = $slot;
           if ($from <= $t_end && $to > $t) {
-            $status = self::FREEBUSY_BUSY;
+            $status = isset($type) ? $type : self::FREEBUSY_BUSY;
             break;
           }
         }
diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index 6530a012..bfa2614d 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -42,10 +42,12 @@ function rcube_calendar_ui(settings)
     var gmt_offset = (new Date().getTimezoneOffset() / -60) - (settings.timezone || 0);
     var day_clicked = day_clicked_ts = 0;
     var ignore_click = false;
+    var event_defaults = { free_busy:'busy' };
     var event_attendees = null;
     var attendees_list;
-    var freebusy_ui = {};
+    var freebusy_ui = { workinhoursonly:false };
     var freebusy_data = {};
+    var freebusy_needsupdate;
 
     // general datepicker settings
     var datepicker_settings = {
@@ -329,7 +331,9 @@ function rcube_calendar_ui(settings)
       
       var $dialog = $("#eventedit");
       var calendar = event.calendar && me.calendars[event.calendar] ? me.calendars[event.calendar] : { editable:action=='new' };
-      me.selected_event = event;
+      me.selected_event = $.extend(event_defaults, event);  // clone event object (with defaults)
+      event = me.selected_event; // change reference to clone
+      freebusy_needsupdate = false;
 
       // reset dialog first, enable/disable fields according to editable state
       $('#eventtabs').get(0).reset();
@@ -614,27 +618,34 @@ function rcube_calendar_ui(settings)
         return false;
       
       // set form elements
-      var duration = Math.round((event.end.getTime() - event.start.getTime()) / 1000);
-      var startdate = $('#schedule-startdate').val($.fullCalendar.formatDate(event.start, settings['date_format'])).data('duration', duration);
-      var starttime = $('#schedule-starttime').val($.fullCalendar.formatDate(event.start, settings['time_format'])).show();
-      var enddate = $('#schedule-enddate').val($.fullCalendar.formatDate(event.end, settings['date_format']));
-      var endtime = $('#schedule-endtime').val($.fullCalendar.formatDate(event.end, settings['time_format'])).show();
       var allday = $('#edit-allday').get(0);
+      var duration = Math.round((event.end.getTime() - event.start.getTime()) / 1000);
+      freebusy_ui.startdate = $('#schedule-startdate').val($.fullCalendar.formatDate(event.start, settings['date_format'])).data('duration', duration);
+      freebusy_ui.starttime = $('#schedule-starttime').val($.fullCalendar.formatDate(event.start, settings['time_format'])).show();
+      freebusy_ui.enddate = $('#schedule-enddate').val($.fullCalendar.formatDate(event.end, settings['date_format']));
+      freebusy_ui.endtime = $('#schedule-endtime').val($.fullCalendar.formatDate(event.end, settings['time_format'])).show();
       
       if (allday.checked) {
         starttime.val("00:00").hide();
         endtime.val("23:59").hide();
+        event.allDay = true;
       }
       
+      // read attendee roles from drop-downs
+      $('select.edit-attendee-role').each(function(i, elem){
+        if (event_attendees[i])
+          event_attendees[i].role = $(elem).val();
+      });
+      
       // render time slots
       var now = new Date(), fb_start = new Date(), fb_end = new Date();
-      fb_start.setTime(Math.max(now, event.start));
+      fb_start.setTime(event.start);
       fb_start.setHours(0); fb_start.setMinutes(0); fb_start.setSeconds(0); fb_start.setMilliseconds(0);
       fb_end.setTime(fb_start.getTime() + 86400000);
       
       freebusy_data = {};
-      freebusy_ui.loading = 1;  // prevent render_freebusy_grid() to load data
-      freebusy_ui.numdays = allday.checked ? 7 : 1;
+      freebusy_ui.loading = 1;  // prevent render_freebusy_grid() to load data yet
+      freebusy_ui.numdays = allday.checked ? 7 : Math.ceil(duration * 2 / 86400);
       freebusy_ui.interval = allday.checked ? 360 : 60;
       freebusy_ui.start = fb_start;
       freebusy_ui.end = new Date(freebusy_ui.start.getTime() + 86400000 * freebusy_ui.numdays);
@@ -651,9 +662,23 @@ function rcube_calendar_ui(settings)
       
       $('#schedule-attendees-list').html(list_html);
       
+      // enable/disable buttons
+      $('#shedule-find-prev').button('option', 'disabled', (fb_start.getTime() < now.getTime()));
+      
       // dialog buttons
       var buttons = {};
       
+      buttons[rcmail.gettext('adobt', 'calendar')] = function() {
+        $('#edit-startdate').val(freebusy_ui.startdate.val());
+        $('#edit-starttime').val(freebusy_ui.starttime.val());
+        $('#edit-enddate').val(freebusy_ui.enddate.val());
+        $('#edit-endtime').val(freebusy_ui.endtime.val());
+        if (freebusy_needsupdate)
+          update_freebusy_status(me.selected_event);
+        freebusy_needsupdate = false;
+        $dialog.dialog("close");
+      };
+      
       buttons[rcmail.gettext('cancel', 'calendar')] = function() {
         $dialog.dialog("close");
       };
@@ -664,6 +689,8 @@ function rcube_calendar_ui(settings)
         closeOnEscape: true,
         title: rcmail.gettext('scheduletime', 'calendar'),
         close: function() {
+          if (bw.ie6)
+            $("#edit-attendees-table").css('visibility','visible');
           $dialog.dialog("destroy").hide();
         },
         buttons: buttons,
@@ -671,6 +698,18 @@ function rcube_calendar_ui(settings)
         width: 850
       }).show();
       
+      // hide edit dialog on IE6 because of drop-down elements
+      if (bw.ie6)
+        $("#edit-attendees-table").css('visibility','hidden');
+      
+      // adjust dialog size to fit grid without scrolling
+      var gridw = $('#schedule-freebusy-times').width();
+      var overflow = gridw - $('#attendees-freebusy-table td.times').width() + 1;
+      if (overflow > 0) {
+        $dialog.dialog('option', 'width', Math.min((window.innerWidth || document.documentElement.clientWidth) - 40, 850 + overflow));
+        $dialog.dialog('option', 'position', ['center', 'center']);
+      }
+      
       // fetch data from server
       freebusy_ui.loading = 0;
       load_freebusy_data(freebusy_ui.start, freebusy_ui.interval);
@@ -694,8 +733,8 @@ function rcube_calendar_ui(settings)
           lastdate = datestr;
         }
         
-        // TODO: define working hours by config
-        css = (freebusy_ui.numdays == 1 && (curdate.getHours() < 6 || curdate.getHours() > 18)) ? 'offhours' : 'workinghours';
+        // set css class according to working hours
+        css = (freebusy_ui.numdays == 1 && (curdate.getHours() < settings['work_start'] || curdate.getHours() > settings['work_end'])) ? 'offhours' : 'workinghours';
         times_row += '<td class="' + css + '">' + Q($.fullCalendar.formatDate(curdate, settings['time_format'])) + '</td>';
         slots_row += '<td class="' + css + ' unknown">&nbsp;</td>';
         
@@ -712,23 +751,98 @@ function rcube_calendar_ui(settings)
         times_html += '<tr id="fbrow' + domid + '">' + slots_row + '</tr>';
       }
       
-      $('#schedule-freebusy-times > thead').html(dates_row + times_row);
-      $('#schedule-freebusy-times > tbody').html(times_html);
+      var table = $('#schedule-freebusy-times');
+      table.children('thead').html(dates_row + times_row);
+      table.children('tbody').html(times_html);
       
       // if we have loaded free-busy data, show it
       if (!freebusy_ui.loading) {
         if (date2unixtime(freebusy_ui.start) < freebusy_data.start || date2unixtime(freebusy_ui.end) > freebusy_data.end || freebusy_ui.interval != freebusy_data.interval) {
-          load_freebusy_data(freebusy_ui.start, freebusy_ui.interval)
-          return;
+          load_freebusy_data(freebusy_ui.start, freebusy_ui.interval);
         }
-        
-        for (var email, i=0; i < event_attendees.length; i++) {
-          if ((email = event_attendees[i].email))
-            update_freebusy_display(email);
+        else {
+          for (var email, i=0; i < event_attendees.length; i++) {
+            if ((email = event_attendees[i].email))
+              update_freebusy_display(email);
+          }
         }
       }
+      
+      // render current event date/time selection over grid table
+      // use timeout to let the dom attributes (width/height/offset) be set first
+      window.setTimeout(function(){ render_freebusy_overlay(); }, 10);
     };
     
+    // render overlay element over the grid to visiualize the current event date/time
+    var render_freebusy_overlay = function()
+    {
+      var overlay = $('#schedule-event-time');
+      if (me.selected_event.end.getTime() < freebusy_ui.start.getTime() || me.selected_event.start.getTime() > freebusy_ui.end.getTime()) {
+        overlay.draggable('disable').hide();
+      }
+      else {
+        var table = $('#schedule-freebusy-times'),
+          width = 0,
+          pos = { top:table.children('thead').height(), left:0 },
+          eventstart = date2unixtime(me.selected_event.start),
+          eventend = date2unixtime(me.selected_event.end),
+          slotstart = date2unixtime(freebusy_ui.start),
+          slotsize = freebusy_ui.interval * 60,
+          slotend, fraction, $cell;
+        
+        // iterate through slots to determine position and size of the overlay
+        table.children('thead').find('td').each(function(i, cell){
+          slotend = slotstart + slotsize - 60;
+          // event starts in this slot: compute left
+          if (eventstart >= slotstart && eventstart <= slotend) {
+            fraction = 1 - (slotend - eventstart) / slotsize;
+            pos.left = Math.round(cell.offsetLeft + cell.offsetWidth * fraction);
+          }
+          // event ends in this slot: compute width
+          else if (eventend >= slotstart && eventend <= slotend) {
+            fraction = 1 - (slotend - eventend) / slotsize;
+            width = Math.round(cell.offsetLeft + cell.offsetWidth * fraction) - pos.left;
+          }
+
+          slotstart = slotstart + slotsize;
+        });
+
+        if (!width)
+          width = table.width() - pos.left;
+
+        // overlay is visible
+        if (width > 0) {
+          overlay.css({ width: (width-5)+'px', height:(table.children('tbody').height() - 4)+'px', left:pos.left+'px', top:pos.top+'px' }).draggable('enable').show();
+          
+          // configure draggable
+          if (!overlay.data('isdraggable')) {
+            overlay.draggable({
+              axis: 'x',
+              scroll: true,
+              stop: function(e, ui){
+                // convert pixels to time
+                var px = ui.position.left;
+                var range_p = $('#schedule-freebusy-times').width();
+                var range_t = freebusy_ui.end.getTime() - freebusy_ui.start.getTime();
+                var newstart = new Date(freebusy_ui.start.getTime() + px * (range_t / range_p));
+                newstart.setSeconds(0); newstart.setMilliseconds(0);
+                // round to 5 minutes
+                var round = newstart.getMinutes() % 5;
+                if (round > 2.5) newstart.setTime(newstart.getTime() + (5 - round) * 60000);
+                else if (round > 0) newstart.setTime(newstart.getTime() - round * 60000);
+                // update event times
+                update_freebusy_dates(newstart, new Date(newstart.getTime() + freebusy_ui.startdate.data('duration') * 1000));
+              }
+            }).data('isdraggable', true);
+          }
+        }
+        else
+          overlay.draggable('disable').hide();
+      }
+      
+    };
+    
+    
     // fetch free-busy information for each attendee from server
     var load_freebusy_data = function(from, interval)
     {
@@ -790,6 +904,109 @@ function rcube_calendar_ui(settings)
         });
       }
     };
+    
+    // write changed event date/times back to form fields
+    var update_freebusy_dates = function(start, end)
+    {
+      me.selected_event.start = start;
+      me.selected_event.end = end;
+      freebusy_ui.startdate.val($.fullCalendar.formatDate(start, settings['date_format']));
+      freebusy_ui.starttime.val($.fullCalendar.formatDate(start, settings['time_format']));
+      freebusy_ui.enddate.val($.fullCalendar.formatDate(end, settings['date_format']));
+      freebusy_ui.endtime.val($.fullCalendar.formatDate(end, settings['time_format']));
+      freebusy_needsupdate = true;
+    };
+
+    // attempt to find a time slot where all attemdees are available
+    var freebusy_find_slot = function(dir)
+    {
+      var event = me.selected_event,
+        eventstart = date2unixtime(event.start),  // calculate with unitimes
+        eventend = date2unixtime(event.end),
+        duration = eventend - eventstart,
+        sinterval = freebusy_data.interval * 60,
+        intvlslots = event.allDay ? 4 : 1,
+        numslots = Math.ceil(duration / sinterval),
+        checkdate, slotend, email, curdate;
+
+      // shift event times to next possible slot
+      eventstart += sinterval * intvlslots * dir;
+      eventend += sinterval * intvlslots * dir;
+
+      // iterate through free-busy slots and find candidates
+      var candidatecount = 0, candidatestart = candidateend = success = false;
+      for (var slot = dir > 0 ? freebusy_data.start : freebusy_data.end - sinterval; (dir > 0 && slot < freebusy_data.end) || (dir < 0 && slot >= freebusy_data.start); slot += sinterval * dir) {
+        slotend = slot + sinterval;
+        if ((dir > 0 && slotend <= eventstart) || (dir < 0 && slot >= eventend))  // skip
+          continue;
+        
+        // respect workingours setting
+        if (freebusy_ui.workinhoursonly && freebusy_data.interval <= 60) {
+          curdate = fromunixtime(dir > 0 || !candidateend ? slot : (candidateend - duration));
+          if (curdate.getHours() < settings['work_start'] || curdate.getHours() > settings['work_end']) {  // skip off-hours
+            candidatestart = candidateend = false;
+            candidatecount = 0;
+            continue;
+          }
+        }
+        
+        if (!candidatestart)
+          candidatestart = slot;
+        
+        // check freebusy data for all attendees
+        for (var i=0; i < event_attendees.length; i++) {
+          if ((email = event_attendees[i].email) && freebusy_data[email][slot] > 1) {
+            candidatestart = candidateend = false;
+            break;
+          }
+        }
+        
+        // occupied slot
+        if (!candidatestart) {
+          slot += Math.max(0, intvlslots - candidatecount - 1) * sinterval * dir;
+          candidatecount = 0;
+          continue;
+        }
+        
+        // set candidate end to slot end time
+        candidatecount++;
+        if (dir < 0 && !candidateend)
+          candidateend = slotend;
+        
+        // if candidate is big enough, this is it!
+        if (candidatecount == numslots) {
+          if (dir > 0) {
+            event.start = fromunixtime(candidatestart);
+            event.end = fromunixtime(candidatestart + duration);
+          }
+          else {
+            event.end = fromunixtime(candidateend);
+            event.start = fromunixtime(candidateend - duration);
+          }
+          success = true;
+          break;
+        }
+      }
+      
+      // update event date/time display
+      if (success) {
+        update_freebusy_dates(event.start, event.end);
+        
+        // move freebusy grid if necessary
+        if (event.start.getTime() >= freebusy_ui.end.getTime())
+          render_freebusy_grid(1);
+        else if (event.end.getTime() <= freebusy_ui.start.getTime())
+          render_freebusy_grid(-1);
+        else
+          render_freebusy_overlay();
+        
+        var now = new Date();
+        $('#shedule-find-prev').button('option', 'disabled', (event.start.getTime() < now.getTime()));
+      }
+      else {
+        alert(rcmail.gettext('noslotfound','calendar'));
+      }
+    };
 
 
     // update event properties and attendees availability if event times have changed
@@ -797,10 +1014,11 @@ function rcube_calendar_ui(settings)
     {
       if (me.selected_event) {
         var allday = $('#edit-allday').get(0);
+        me.selected_event.allDay = allday.checked;
         me.selected_event.start = parse_datetime(allday.checked ? '00:00' : $('#edit-starttime').val(), $('#edit-startdate').val());
         me.selected_event.end   = parse_datetime(allday.checked ? '23:59' : $('#edit-endtime').val(), $('#edit-enddate').val());
-        if (me.selected_event.attendees)
-          update_freebusy_status(me.selected_event);
+        if (event_attendees)
+          freebusy_needsupdate = true;
         $('#edit-startdate').data('duration', Math.round((me.selected_event.end.getTime() - me.selected_event.start.getTime()) / 1000));
       }
     };
@@ -902,10 +1120,12 @@ function rcube_calendar_ui(settings)
     var update_freebusy_status = function(event)
     {
       var icons = attendees_list.find('img.availabilityicon');
-      for (var i=0; i < event.attendees.length; i++) {
-        if (icons.get(i) && event.attendees[i].email && event.attendees[i].status != 'ACCEPTED')
-          check_freebusy_status(icons.get(i), event.attendees[i].email, event);
+      for (var i=0; i < event_attendees.length; i++) {
+        if (icons.get(i) && event_attendees[i].email && event_attendees[i].status != 'ACCEPTED')
+          check_freebusy_status(icons.get(i), event_attendees[i].email, event);
       }
+      
+      freebusy_needsupdate = false;
     };
     
     // load free-busy status from server and update icon accordingly
@@ -1372,8 +1592,10 @@ function rcube_calendar_ui(settings)
       // callback for clicks in all-day box
       dayClick: function(date, allDay, e, view) {
         var now = new Date().getTime();
-        if (now - day_clicked_ts < 400 && day_clicked == date.getTime())  // emulate double-click on day
-          return event_edit_dialog('new', { start:date, end:date, allDay:allDay, calendar:me.selected_calendar });
+        if (now - day_clicked_ts < 400 && day_clicked == date.getTime()) {  // emulate double-click on day
+          var enddate = new Date(); enddate.setTime(date.getTime() + 86400000 - 60000);
+          return event_edit_dialog('new', { start:date, end:enddate, allDay:allDay, calendar:me.selected_calendar });
+        }
         
         if (!ignore_click) {
           view.calendar.gotoDate(date);
@@ -1563,14 +1785,17 @@ function rcube_calendar_ui(settings)
     // init event dialog
     $('#eventtabs').tabs({
       show: function(event, ui) {
-        if (ui.panel.id == 'event-tab-3')
+        if (ui.panel.id == 'event-tab-3') {
           $('#edit-attendee-name').select();
+          if (freebusy_needsupdate && me.selected_event)
+            update_freebusy_status(me.selected_event);
+        }
       }
     });
     $('#edit-enddate, input.edit-alarm-date').datepicker(datepicker_settings);
     $('#edit-startdate').datepicker(datepicker_settings).datepicker('option', 'onSelect', shift_enddate).change(function(){ shift_enddate(this.value); });
     $('#edit-enddate').datepicker('option', 'onSelect', event_times_changed).change(event_times_changed);
-    $('#edit-allday').click(function(){ $('#edit-starttime, #edit-endtime')[(this.checked?'hide':'show')](); });
+    $('#edit-allday').click(function(){ $('#edit-starttime, #edit-endtime')[(this.checked?'hide':'show')](); event_times_changed(); });
 
     // configure drop-down menu on time input fields based on jquery UI autocomplete
     $('#edit-starttime, #edit-endtime, input.edit-alarm-time')
@@ -1630,13 +1855,17 @@ function rcube_calendar_ui(settings)
       event_freebusy_dialog();
     });
     
-    $('#shedule-freebusy-prev').button().click(function(){ render_freebusy_grid(-1); });
-    $('#shedule-freebusy-next').button().click(function(){ render_freebusy_grid(1); }).parent().buttonset();
-
+    $('#shedule-freebusy-prev').html(bw.ie6 ? '&lt;&lt;' : '&#9668;').button().click(function(){ render_freebusy_grid(-1); });
+    $('#shedule-freebusy-next').html(bw.ie6 ? '&gt;&gt;' : '&#9658;').button().click(function(){ render_freebusy_grid(1); }).parent().buttonset();
+    
+    $('#shedule-find-prev').button().click(function(){ freebusy_find_slot(-1); });
+    $('#shedule-find-next').button().click(function(){ freebusy_find_slot(1); });
+    
     $('#schedule-freebusy-wokinghours').click(function(){
+      freebusy_ui.workinhoursonly = this.checked;
       $('#workinghourscss').remove();
       if (this.checked)
-        $('<style type="text/css" id="workinghourscss"> td.offhours { display:none } </style>').appendTo('head');
+        $('<style type="text/css" id="workinghourscss"> td.offhours { opacity:0.3; filter:alpha(opacity=30) } </style>').appendTo('head');
     });
 
     // add proprietary css styles if not IE
diff --git a/plugins/calendar/config.inc.php.dist b/plugins/calendar/config.inc.php.dist
index aa580071..a6b23415 100644
--- a/plugins/calendar/config.inc.php.dist
+++ b/plugins/calendar/config.inc.php.dist
@@ -52,6 +52,12 @@ $rcmail_config['calendar_first_day'] = 1;
 // first hour of the calendar (0-23)
 $rcmail_config['calendar_first_hour'] = 6;
 
+// working hours begin
+$rcmail_config['calendar_work_start'] = 6;
+
+// working hours end
+$rcmail_config['calendar_work_end'] = 18;
+
 // event categories
 $rcmail_config['calendar_categories'] = array(
   'Personal' => 'c0c0c0',
diff --git a/plugins/calendar/drivers/kolab/kolab_calendar.php b/plugins/calendar/drivers/kolab/kolab_calendar.php
index 816a9444..50b06ed0 100644
--- a/plugins/calendar/drivers/kolab/kolab_calendar.php
+++ b/plugins/calendar/drivers/kolab/kolab_calendar.php
@@ -67,9 +67,11 @@ class kolab_calendar
       }
       else {
         $acl = $this->storage->_folder->getACL();
-        $acl = $acl[$_SESSION['username']];
-        if (strpos($acl, 'i') !== false)
-          $this->readonly = false;
+        if (is_array($acl)) {
+          $acl = $acl[$_SESSION['username']];
+          if (strpos($acl, 'i') !== false)
+            $this->readonly = false;
+        }
       }
     }
   }
diff --git a/plugins/calendar/drivers/kolab/kolab_driver.php b/plugins/calendar/drivers/kolab/kolab_driver.php
index 2b22320e..0430bb0d 100644
--- a/plugins/calendar/drivers/kolab/kolab_driver.php
+++ b/plugins/calendar/drivers/kolab/kolab_driver.php
@@ -693,9 +693,16 @@ class kolab_driver extends calendar_driver
     if (empty($email)/* || $end < time()*/)
       return false;
     
+    // map vcalendar fbtypes to internal values
+    $fbtypemap = array(
+      'FREE' => calendar::FREEBUSY_FREE,
+      'BUSY-TENTATIVE' => calendar::FREEBUSY_TENTATIVE,
+      'X-OUT-OF-OFFICE' => calendar::FREEBUSY_OOF,
+      'OOF' => calendar::FREEBUSY_OOF);
+    
     // ask kolab server first
     $fbdata = @file_get_contents(rcube_kolab::get_freebusy_url($email));
-      
+
     // get free-busy url from contacts
     if (!$fbdata) {
       $fburl = null;
@@ -722,10 +729,12 @@ class kolab_driver extends calendar_driver
       $fbcal->parsevCalendar($fbdata);
       if ($fb = $fbcal->findComponent('vfreebusy')) {
         $result = array();
+        $params = $fb->getExtraParams();
         foreach ($fb->getBusyPeriods() as $from => $to) {
           if ($to == null)  // no information, assume free
             break;
-          $result[] = array($from, $to);
+          $type = $params[$from]['FBTYPE'];
+          $result[] = array($from, $to, isset($fbtypemap[$type]) ? $fbtypemap[$type] : calendar::FREEBUSY_BUSY);
         }
         
         return $result;
diff --git a/plugins/calendar/lib/calendar_ical.php b/plugins/calendar/lib/calendar_ical.php
index 66cd9ee9..d2e06cb5 100644
--- a/plugins/calendar/lib/calendar_ical.php
+++ b/plugins/calendar/lib/calendar_ical.php
@@ -67,7 +67,7 @@ class calendar_ical
         $ical .= "DTSTART:" . gmdate('Ymd\THis\Z', $event['start']) . "\r\n";
         $ical .= "DTEND:" . gmdate('Ymd\THis\Z', $event['end']) . "\r\n";
         $ical .= "SUMMARY:" . self::escpape($event['title']) . "\r\n";
-        $ical .= "DESCRIPTION:" . wordwrap(self::escpape($event['description']),75,'\r\n ') . "\r\n";
+        $ical .= "DESCRIPTION:" . wordwrap(self::escpape($event['description']),75,"\r\n ") . "\r\n";
 		
 		if (!empty($event['attendees'])){
 				
diff --git a/plugins/calendar/lib/calendar_ui.php b/plugins/calendar/lib/calendar_ui.php
index 4d90826a..30d44ea5 100644
--- a/plugins/calendar/lib/calendar_ui.php
+++ b/plugins/calendar/lib/calendar_ui.php
@@ -592,10 +592,13 @@ class calendar_ui
     $table->add('attendees',
       html::tag('h3', 'boxtitle', $this->calendar->gettext('tabattendees')) .
       html::div('timesheader', '&nbsp;') .
-      html::div(array('id' => 'schedule-attendees-list'), '')
+      html::div(array('id' => 'schedule-attendees-list', 'class' => 'attendees-list'), '')
     );
     $table->add('times',
-      html::div('scroll', html::tag('table', array('id' => 'schedule-freebusy-times', 'border' => 0, 'cellspacing' => 0), html::tag('thead') . html::tag('tbody')))
+      html::div('scroll',
+        html::tag('table', array('id' => 'schedule-freebusy-times', 'border' => 0, 'cellspacing' => 0), html::tag('thead') . html::tag('tbody')) .
+        html::div(array('id' => 'schedule-event-time', 'style' => 'display:none'), '&nbsp;')
+      )
     );
     
     return $table->show($attrib);
diff --git a/plugins/calendar/localization/en_US.inc b/plugins/calendar/localization/en_US.inc
index a4a8a509..4b405ee5 100644
--- a/plugins/calendar/localization/en_US.inc
+++ b/plugins/calendar/localization/en_US.inc
@@ -31,6 +31,7 @@ $labels['edit'] = 'Edit';
 $labels['save'] = 'Save';
 $labels['remove'] = 'Remove';
 $labels['cancel'] = 'Cancel';
+$labels['adobt'] = 'Adopt changes';
 $labels['print'] = 'Print calendars';
 $labels['title'] = 'Summary';
 $labels['description'] = 'Description';
@@ -95,10 +96,14 @@ $labels['roleresource'] = 'Resource';
 $labels['availfree'] = 'Free';
 $labels['availbusy'] = 'Busy';
 $labels['availunknown'] = 'Unknown';
+$labels['availtentative'] = 'Tentative';
 $labels['availoutofoffice'] = 'Out of Office';
 $labels['scheduletime'] = 'Available times';
 $labels['sendnotifications'] = 'Send notifications';
-$labels['onlyworkinghours'] = 'Show only working hours';
+$labels['onlyworkinghours'] = 'Only working hours';
+$labels['prevslot'] = 'Previous Slot';
+$labels['nextslot'] = 'Next Slot';
+$labels['noslotfound'] = 'Unable to find a free time slot';
 
 // event dialog tabs
 $labels['tabsummary'] = 'Summary';
diff --git a/plugins/calendar/skins/default/calendar.css b/plugins/calendar/skins/default/calendar.css
index 47e47e8c..64669a92 100644
--- a/plugins/calendar/skins/default/calendar.css
+++ b/plugins/calendar/skins/default/calendar.css
@@ -36,6 +36,7 @@ body.calendarmain {
 
 #datepicker .ui-datepicker {
 	width: 97% !important;
+	box-shadow: none;
 	-moz-box-shadow: none;
 	-webkit-box-shadow: none;
 }
@@ -566,7 +567,7 @@ td.topalign {
 }
 
 .availability img.availabilityicon.loading {
-	background: url('images/loading-small.gif') top left no-repeat;
+	background: url('images/loading-small.gif') middle middle no-repeat;
 }
 
 #schedule-freebusy-times td.unknown,
@@ -584,6 +585,11 @@ td.topalign {
 	background: #c00;
 }
 
+#schedule-freebusy-times td.tentative,
+.availability img.availabilityicon.tentative {
+	background: #66d;
+}
+
 #schedule-freebusy-times td.out-of-office,
 .availability img.availabilityicon.out-of-office {
 	background: #f0b400;
@@ -591,6 +597,7 @@ td.topalign {
 
 #edit-attendees-legend {
 	margin-top: 3em;
+	margin-bottom: 0.5em;
 }
 
 #edit-attendees-legend .legend {
@@ -651,6 +658,7 @@ td.topalign {
 }
 
 #attendees-freebusy-table div.scroll {
+	position: relative;
 	overflow: auto;
 }
 
@@ -660,17 +668,33 @@ td.topalign {
 	border-color: #ccc;
 }
 
-#attendees-freebusy-table div.timesheader {
-	padding: 0.3em;
+.attendees-list .attendee {
+	padding: 3px 4px 3px 20px;
+	background: url('images/attendee-status.gif') 2px -97px no-repeat;
 }
 
-#schedule-attendees-list div.attendee {
-	padding: 3px 20px 3px 6px;
+.attendees-list div.attendee {
 	border-top: 1px solid #ccc;
 }
 
-#schedule-attendees-list div.loading {
-	background: url('images/loading-small.gif') top right no-repeat;
+.attendees-list span.attendee {
+	margin-right: 2em;
+}
+
+.attendees-list .organizer {
+	background-position: 3px -77px;
+}
+
+.attendees-list .opt-participant {
+	background-position: 2px -117px;
+}
+
+.attendees-list .chair {
+	background-position: 2px -137px;
+}
+
+.attendees-list .loading {
+	background: url('images/loading-small.gif') 1px 50% no-repeat;
 }
 
 #schedule-freebusy-times {
@@ -688,6 +712,7 @@ td.topalign {
 	border-width: 0 1px 0 1px;
 }
 
+#attendees-freebusy-table div.timesheader,
 #schedule-freebusy-times tr.times td {
 	min-width: 30px;
 	font-size: 9px;
@@ -695,9 +720,19 @@ td.topalign {
 	text-align: center;
 }
 
+#schedule-event-time {
+	position: absolute;
+	border: 2px solid #333;
+	background: #777;
+	background: rgba(60, 60, 60, 0.6);
+	opacity: 0.5;
+	border-radius: 4px;
+	cursor: move;
+}
+
 #eventfreebusy .schedule-options {
 	position: relative;
-	margin-bottom: 2em;
+	margin-bottom: 1.5em;
 }
 
 #eventfreebusy .schedule-buttons {
@@ -706,6 +741,15 @@ td.topalign {
 	right: 0;
 }
 
+#eventfreebusy .schedule-find-buttons {
+	padding-bottom:0.5em;
+}
+
+#eventfreebusy .schedule-find-buttons button {
+	min-width: 9em;
+	text-align: center;
+}
+
 span.edit-alarm-set {
 	white-space: nowrap;
 }
diff --git a/plugins/calendar/skins/default/iehacks.css b/plugins/calendar/skins/default/iehacks.css
index fa282176..31f82d78 100644
--- a/plugins/calendar/skins/default/iehacks.css
+++ b/plugins/calendar/skins/default/iehacks.css
@@ -43,3 +43,12 @@ html #calendartoolbar a.buttonPas {
 .fc-header-title h2 {
 	font-size: 16px;
 }
+
+#schedule-event-time {
+	filter: alpha(opacity=40);
+}
+
+#eventfreebusy .schedule-buttons,
+#edit-attendees-form #edit-attendee-schedule {
+	right: 0.6em;
+}
\ No newline at end of file
diff --git a/plugins/calendar/skins/default/images/attendee-status.gif b/plugins/calendar/skins/default/images/attendee-status.gif
index a5f65a02..5c08aae3 100644
Binary files a/plugins/calendar/skins/default/images/attendee-status.gif and b/plugins/calendar/skins/default/images/attendee-status.gif differ
diff --git a/plugins/calendar/skins/default/templates/calendar.html b/plugins/calendar/skins/default/templates/calendar.html
index bf83f030..de0419cc 100644
--- a/plugins/calendar/skins/default/templates/calendar.html
+++ b/plugins/calendar/skins/default/templates/calendar.html
@@ -188,25 +188,42 @@
   <roundcube:object name="plugin.attendees_freebusy_table" id="attendees-freebusy-table" cellspacing="0" cellpadding="0" border="0" />
   
   <div class="schedule-options">
-    <label><input type="checkbox" id="schedule-freebusy-wokinghours" value="1" /><roundcube:label name="calendar.onlyworkinghours" /></label>
+    &nbsp;
     <div class="schedule-buttons">
-      <button id="shedule-freebusy-prev" title="<roundcube:label name='previouspage' />">&#9668;</button>
-      <button id="shedule-freebusy-next" title="<roundcube:label name='nextpage' />">&#9658;</button>
+      <button id="shedule-freebusy-prev" title="<roundcube:label name='previouspage' />">&#9668;</button><button id="shedule-freebusy-next" title="<roundcube:label name='nextpage' />">&#9658;</button>
     </div>
   </div>
   
-  <div class="form-section">
-    <label for="schedule-startdate"><roundcube:label name="calendar.start" /></label>
-    <input type="text" name="startdate" size="10" id="schedule-startdate" disabled="true" /> &nbsp;
-    <input type="text" name="starttime" size="6" id="schedule-starttime" disabled="true" />
+  <div style="float:left; width:28em">
+    <div class="form-section">
+      <label for="schedule-startdate"><roundcube:label name="calendar.start" /></label>
+      <input type="text" name="startdate" size="10" id="schedule-startdate" disabled="true" /> &nbsp;
+      <input type="text" name="starttime" size="6" id="schedule-starttime" disabled="true" />
+    </div>
+    <div class="form-section">
+      <label for="schedule-enddate"><roundcube:label name="calendar.end" /></label>
+      <input type="text" name="enddate" size="10" id="schedule-enddate" disabled="true" /> &nbsp;
+      <input type="text" name="endtime" size="6"  id="schedule-endtime" disabled="true" />
+    </div>
   </div>
-  <div class="form-section">
-    <label for="schedule-enddate"><roundcube:label name="calendar.end" /></label>
-    <input type="text" name="enddate" size="10" id="schedule-enddate" disabled="true" /> &nbsp;
-    <input type="text" name="endtime" size="6"  id="schedule-endtime" disabled="true" />
+  <div style="float:left">
+    <div class="schedule-find-buttons">
+      <button id="shedule-find-prev">&#9668; <roundcube:label name="calendar.prevslot" /></button>
+      <button id="shedule-find-next"><roundcube:label name="calendar.nextslot" /> &#9658;</button>
+    </div>
+    <div class="schedule-options">
+      <label><input type="checkbox" id="schedule-freebusy-wokinghours" value="1" /><roundcube:label name="calendar.onlyworkinghours" /></label>
+    </div>
   </div>
+  <br style="clear:both;" />
   
   <roundcube:include file="/templates/freebusylegend.html" />
+  <div class="attendees-list">
+    <span class="attendee organizer"><roundcube:label name="calendar.roleorganizer" /></span>
+    <span class="attendee req-participant"><roundcube:label name="calendar.rolerequired" /></span>
+    <span class="attendee opt-participant"><roundcube:label name="calendar.roleoptional" /></span>
+    <span class="attendee chair"><roundcube:label name="calendar.roleresource" /></span>
+  </div>
 </div>
 
 <div id="calendarform" class="uidialog">
diff --git a/plugins/calendar/skins/default/templates/freebusylegend.html b/plugins/calendar/skins/default/templates/freebusylegend.html
index c3d0a86e..5cc01a18 100644
--- a/plugins/calendar/skins/default/templates/freebusylegend.html
+++ b/plugins/calendar/skins/default/templates/freebusylegend.html
@@ -1,6 +1,7 @@
   <div id="edit-attendees-legend" class="availability">
     <span class="legend"><img class="availabilityicon free" src="./program/blank.gif" /> <roundcube:label name="calendar.availfree" /></span>
     <span class="legend"><img class="availabilityicon busy" src="./program/blank.gif" /> <roundcube:label name="calendar.availbusy" /></span>
+    <span class="legend"><img class="availabilityicon tentative" src="./program/blank.gif" /> <roundcube:label name="calendar.availtentative" /></span>
     <span class="legend"><img class="availabilityicon out-of-office" src="./program/blank.gif" /> <roundcube:label name="calendar.availoutofoffice" /></span>
     <span class="legend"><img class="availabilityicon unknown" src="./program/blank.gif" /> <roundcube:label name="calendar.availunknown" /></span>
   </div>
diff --git a/plugins/kolab_addressbook/kolab_addressbook.js b/plugins/kolab_addressbook/kolab_addressbook.js
index cdb525d1..9cb1756e 100644
--- a/plugins/kolab_addressbook/kolab_addressbook.js
+++ b/plugins/kolab_addressbook/kolab_addressbook.js
@@ -191,7 +191,7 @@ rcube_webmail.prototype.book_update = function(data, old)
         level = olddata.realname.split(this.env.delimiter).length - data.realname.split(this.env.delimiter).length;
         // update (realname and ID of) subfolders
         for (n in sources) {
-            if (n.indexOf(old) == 0) {
+            if (n != data.id && n.indexOf(old) == 0) {
                 // new ID
                 id = data.id + '-' + n.substr(old.length);
                 name = sources[n].name;
diff --git a/plugins/kolab_addressbook/kolab_addressbook.php b/plugins/kolab_addressbook/kolab_addressbook.php
index 5432ffac..c6178920 100644
--- a/plugins/kolab_addressbook/kolab_addressbook.php
+++ b/plugins/kolab_addressbook/kolab_addressbook.php
@@ -27,7 +27,7 @@
  */
 class kolab_addressbook extends rcube_plugin
 {
-    public $task = 'mail|settings|addressbook';
+    public $task = 'mail|settings|addressbook|calendar';
 
     private $folders;
     private $sources;
@@ -54,6 +54,7 @@ class kolab_addressbook extends rcube_plugin
         // register hooks
         $this->add_hook('addressbooks_list', array($this, 'address_sources'));
         $this->add_hook('addressbook_get', array($this, 'get_address_book'));
+        $this->add_hook('config_get', array($this, 'config_get'));
 
         if ($this->rc->task == 'addressbook') {
             $this->add_texts('localization');
@@ -74,10 +75,6 @@ class kolab_addressbook extends rcube_plugin
             $this->add_hook('preferences_list', array($this, 'prefs_list'));
             $this->add_hook('preferences_save', array($this, 'prefs_save'));
         }
-        // extend list of address sources to be used for autocompletion
-        else if ($this->rc->task == 'mail' && $this->rc->action == 'autocomplete') {
-            $this->autocomplete_sources();
-        }
     }
 
 
@@ -149,16 +146,22 @@ class kolab_addressbook extends rcube_plugin
 
 
     /**
-     * Setts autocomplete_addressbooks option according to
-     * kolab_addressbook_prio setting.
+     * Sets autocomplete_addressbooks option according to
+     * kolab_addressbook_prio setting extending list of address sources
+     * to be used for autocompletion.
      */
-    public function autocomplete_sources()
+    public function config_get($args)
     {
+        if ($args['name'] != 'autocomplete_addressbooks') {
+            return $args;
+        }
+
         // Load configuration
         $this->load_config();
 
         $abook_prio = (int) $this->rc->config->get('kolab_addressbook_prio');
-        $sources    = (array) $this->rc->config->get('autocomplete_addressbooks', array());
+        // here we cannot use rc->config->get()
+        $sources    = $GLOBALS['CONFIG']['autocomplete_addressbooks'];
 
         // Disable all global address books
         // Assumes that all non-kolab_addressbook sources are global
@@ -166,6 +169,10 @@ class kolab_addressbook extends rcube_plugin
             $sources = array();
         }
 
+        if (!is_array($sources)) {
+            $sources = array();
+        }
+
         $kolab_sources = array();
         foreach ($this->_list_sources() as $abook_id => $abook) {
             if (!in_array($abook_id, $sources))
@@ -180,9 +187,11 @@ class kolab_addressbook extends rcube_plugin
             else {
                 $sources = array_merge($sources, $kolab_sources);
             }
-
-            $this->rc->config->set('autocomplete_addressbooks', $sources);
         }
+
+        $args['result'] = $sources;
+
+        return $args;
     }
 
 
diff --git a/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php b/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
index b4c72a4f..6cc0289b 100644
--- a/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
+++ b/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
@@ -128,11 +128,13 @@ class rcube_kolab_contacts extends rcube_addressbook
             }
             else {
                 $acl = $this->storagefolder->getACL();
-                $acl = $acl[$_SESSION['username']];
-                if (strpos($acl, 'i') !== false)
-                    $this->readonly = false;
-                if (strpos($acl, 'a') !== false || strpos($acl, 'x') !== false)
-                    $this->editable = true;
+                if (is_array($acl)) {
+                    $acl = $acl[$_SESSION['username']];
+                    if (strpos($acl, 'i') !== false)
+                        $this->readonly = false;
+                    if (strpos($acl, 'a') !== false || strpos($acl, 'x') !== false)
+                        $this->editable = true;
+                }
             }
         }
     }
@@ -363,6 +365,8 @@ class rcube_kolab_contacts extends rcube_addressbook
                     $search = $value;
                 }
 
+                $s_len = strlen($search);
+
                 foreach ((array)$contact[$col] as $val) {
                     // composite field, e.g. address
                     if (is_array($val)) {
@@ -370,7 +374,9 @@ class rcube_kolab_contacts extends rcube_addressbook
                     }
                     $val = mb_strtolower($val);
 
-                    if (($strict && $val == $search) || (!$strict && strpos($val, $search) !== false)) {
+                    if (($strict && $val == $search)
+                        || (!$strict && $s_len && strpos($val, $search) !== false)
+                    ) {
                         if (!$advanced) {
                             $this->filter['ids'][] = $id;
                             break 2;
@@ -892,6 +898,31 @@ class rcube_kolab_contacts extends rcube_addressbook
         return false;
     }
 
+    /**
+     * Check the given data before saving.
+     * If input not valid, the message to display can be fetched using get_error()
+     *
+     * @param array Associative array with contact data to save
+     *
+     * @return boolean True if input is valid, False if not.
+     */
+    public function validate($save_data)
+    {
+        // validate e-mail addresses
+        $valid = parent::validate($save_data);
+
+        // require at least one e-mail address (syntax check is already done)
+        if ($valid) {
+            if (!strlen($save_data['name'])
+                && !array_filter($this->get_col_values('email', $save_data, true))
+            ) {
+                $this->set_error('warning', 'kolab_addressbook.noemailnamewarning');
+                $valid = false;
+            }
+        }
+
+        return $valid;
+    }
 
     /**
      * Establishes a connection to the Kolab_Data object for accessing contact data
@@ -903,7 +934,6 @@ class rcube_kolab_contacts extends rcube_addressbook
         }
     }
 
-
     /**
      * Establishes a connection to the Kolab_Data object for accessing groups data
      */
@@ -914,7 +944,6 @@ class rcube_kolab_contacts extends rcube_addressbook
         }
     }
 
-
     /**
      * Simply fetch all records and store them in private member vars
      */
@@ -941,7 +970,6 @@ class rcube_kolab_contacts extends rcube_addressbook
         }
     }
 
-
     /**
      * Callback function for sorting contacts
      */
@@ -950,7 +978,6 @@ class rcube_kolab_contacts extends rcube_addressbook
       return strcasecmp($a['name'], $b['name']);
     }
 
-
     /**
      * Read distribution-lists AKA groups from server
      */
@@ -975,7 +1002,6 @@ class rcube_kolab_contacts extends rcube_addressbook
         }
     }
 
-
     /**
      * Map fields from internal Kolab_Format to Roundcube contact format
      */
@@ -1026,6 +1052,9 @@ class rcube_kolab_contacts extends rcube_addressbook
         return array_filter($out);
     }
 
+    /**
+     * Map fields from Roundcube format to internal Kolab_Format
+     */
     private function _from_rcube_contact($contact)
     {
         $object = array();
diff --git a/plugins/kolab_addressbook/localization/en_US.inc b/plugins/kolab_addressbook/localization/en_US.inc
index ce90f60a..f3cb17ea 100644
--- a/plugins/kolab_addressbook/localization/en_US.inc
+++ b/plugins/kolab_addressbook/localization/en_US.inc
@@ -25,12 +25,13 @@ $labels['globalonly'] = 'Global address book(s) only';
 $messages['bookdeleteconfirm']  = 'Do you really want to delete the selected address book and all contacts in it?';
 $messages['bookdeleting'] = 'Deleting address book...';
 $messages['booksaving'] = 'Saving address book...';
-$messages['bookdeleted'] = 'Address book deleted successfully';
-$messages['bookupdated'] = 'Address book updated successfully';
-$messages['bookcreated'] = 'Address book created successfully';
-$messages['bookdeleteerror'] = 'An error occured while deleting address book';
-$messages['bookupdateerror'] = 'An error occured while updating address book';
-$messages['bookcreateerror'] = 'An error occured while creating address book';
-$messages['nobooknamewarning'] = 'Please, enter address book name';
+$messages['bookdeleted'] = 'Address book deleted successfully.';
+$messages['bookupdated'] = 'Address book updated successfully.';
+$messages['bookcreated'] = 'Address book created successfully.';
+$messages['bookdeleteerror'] = 'An error occured while deleting address book.';
+$messages['bookupdateerror'] = 'An error occured while updating address book.';
+$messages['bookcreateerror'] = 'An error occured while creating address book.';
+$messages['nobooknamewarning'] = 'Please, enter address book name.';
+$messages['noemailnamewarning'] = 'Please, enter email address or contact name.';
 
 ?>
diff --git a/plugins/kolab_addressbook/localization/pl_PL.inc b/plugins/kolab_addressbook/localization/pl_PL.inc
index 61887231..e2735783 100644
--- a/plugins/kolab_addressbook/localization/pl_PL.inc
+++ b/plugins/kolab_addressbook/localization/pl_PL.inc
@@ -25,12 +25,13 @@ $labels['parentbook'] = 'Książka nadrzędna';
 $messages['bookdeleteconfirm'] = 'Czy na pewno chcesz usunąć wybraną książkę i wszystkie kontakty w niej zapisane?';
 $messages['bookdeleting'] = 'Usuwanie książki adresowej...';
 $messages['booksaving'] = 'Zapisywanie książki adresowej...';
-$messages['bookdeleted'] = 'Książka adresowa została usunięta';
-$messages['bookupdated'] = 'Książka adresowa została zaktualizowana';
-$messages['bookcreated'] = 'Książka adresowa została utworzona';
-$messages['bookdeleteerror'] = 'Wystąpił błąd podczas usuwania książki adresowej';
-$messages['bookupdateerror'] = 'Wystąpił błąd podczas zmiany książki adresowej';
-$messages['bookcreateerror'] = 'Wystąpił błąd podczas tworzenia książki adresowej';
-$messages['nobooknamewarning'] = 'Proszę podać nazwę książki adresowej';
+$messages['bookdeleted'] = 'Książka adresowa została usunięta.';
+$messages['bookupdated'] = 'Książka adresowa została zaktualizowana.';
+$messages['bookcreated'] = 'Książka adresowa została utworzona.';
+$messages['bookdeleteerror'] = 'Wystąpił błąd podczas usuwania książki adresowej.';
+$messages['bookupdateerror'] = 'Wystąpił błąd podczas zmiany książki adresowej.';
+$messages['bookcreateerror'] = 'Wystąpił błąd podczas tworzenia książki adresowej.';
+$messages['nobooknamewarning'] = 'Proszę podać nazwę książki adresowej.';
+$messages['noemailnamewarning'] = 'Proszę podać adres email lub nazwę kontaktu.';
 
 ?>
diff --git a/plugins/kolab_core/rcube_kolab.php b/plugins/kolab_core/rcube_kolab.php
index 74b46a86..10cdb36a 100644
--- a/plugins/kolab_core/rcube_kolab.php
+++ b/plugins/kolab_core/rcube_kolab.php
@@ -29,6 +29,8 @@ class rcube_kolab
     private static $horde_auth;
     private static $config;
     private static $ready = false;
+    private static $list;
+    private static $cache;
 
 
     /**
@@ -72,9 +74,11 @@ class rcube_kolab
         // Re-set LDAP/IMAP host config
         $ldap = array('server' => 'ldap://' . $_SESSION['imap_host'] . ':389');
         $imap = array('server' => $_SESSION['imap_host'], 'port' => $_SESSION['imap_port']);
+        $freebusy = array('server' => $_SESSION['imap_host']);
 
         $conf['kolab']['ldap'] = array_merge($ldap, (array)$conf['kolab']['ldap']);
         $conf['kolab']['imap'] = array_merge($imap, (array)$conf['kolab']['imap']);
+        $conf['kolab']['freebusy'] = array_merge($freebusy, (array)$conf['kolab']['freebusy']);
         self::$config = &$conf;
 
         // pass the current IMAP authentication credentials to the Horde auth system
@@ -88,19 +92,57 @@ class rcube_kolab
             );
             Auth::setCredential('password', $pwd);
             self::$ready = true;
-
-            // Register shutdown function for storing folders cache in session
-            // This is already required, because Roundcube session handler
-            // saves data into DB before Horde's shutdown function is called
-            if (!empty($conf['kolab']['imap']['cache_folders'])) {
-                $rcmail->add_shutdown_function(array('rcube_kolab', 'save_folders_cache'));
-            }
         }
 
         NLS::setCharset('UTF-8');
         String::setDefaultCharset('UTF-8');
     }
 
+    /**
+     * Get instance of Kolab_List object
+     *
+     * @return object Kolab_List Folders list object
+     */
+    public static function get_folders_list()
+    {
+        self::setup();
+
+        if (self::$list)
+            return self::$list;
+
+        if (!self::$ready)
+            return null;
+
+        $rcmail = rcmail::get_instance();
+        $imap_cache = $rcmail->config->get('imap_cache');
+
+        if ($imap_cache) {
+            self::$cache = $rcmail->get_cache('IMAP', $imap_cache);
+            self::$list  = self::$cache->get('mailboxes.kolab');
+
+            // Disable Horde folders caching, we're using our own cache
+            self::$config['kolab']['imap']['cache_folders'] = false;
+            // Register shutdown function for saving folders list cache
+            $rcmail->add_shutdown_function(array('rcube_kolab', 'save_folders_list'));
+        }
+
+        if (empty(self::$list)) {
+            self::$list = Kolab_List::singleton();
+        }
+
+        return self::$list;
+    }
+
+    /**
+     * Store Kolab_List instance in Roundcube cache
+     */
+    public static function save_folders_list()
+    {
+        if (self::$cache && self::$list) {
+            self::$cache->set('mailboxes.kolab', self::$list);
+        }
+    }
+
     /**
      * Get instance of a Kolab (XML) format object
      *
@@ -123,8 +165,7 @@ class rcube_kolab
      */
     public static function get_folders($type)
     {
-        self::setup();
-        $kolab = Kolab_List::singleton();
+        $kolab = self::get_folders_list();
         return self::$ready ? $kolab->getByType($type) : array();
     }
 
@@ -136,9 +177,8 @@ class rcube_kolab
      */
     public static function get_folder($folder)
     {
-      self::setup();
-      $kolab = Kolab_List::singleton();
-      return self::$ready ? $kolab->getFolder($folder) : null;
+        $kolab = self::get_folders_list();
+        return self::$ready ? $kolab->getFolder($folder) : null;
     }
 
     /**
@@ -151,8 +191,7 @@ class rcube_kolab
      */
     public static function get_storage($folder, $data_type = null)
     {
-        self::setup();
-        $kolab = Kolab_List::singleton();
+        $kolab = self::get_folders_list();
         return self::$ready ? $kolab->getFolder($folder)->getData($data_type) : null;
     }
 
@@ -175,18 +214,6 @@ class rcube_kolab
             unset($_SESSION['__auth']);
     }
 
-    /**
-     * Save Horde's folders cache in session (workaround shoutdown function issue)
-     */
-    public static function save_folders_cache()
-    {
-        require_once 'Horde/SessionObjects.php';
-
-        $kolab   = Kolab_List::singleton();
-        $session = Horde_SessionObjects::singleton();
-        $session->overwrite('kolab_folderlist', $kolab, false);
-    }
-
     /**
      * Creates folder ID from folder name
      *
@@ -208,8 +235,7 @@ class rcube_kolab
      */
     public static function folder_delete($name)
     {
-        self::setup();
-        $kolab  = Kolab_List::singleton();
+        $kolab = self::get_folders_list();
 
         $folder = $kolab->getFolder($name);
         $result = $folder->delete();
@@ -232,8 +258,7 @@ class rcube_kolab
      */
     public static function folder_create($name, $type=null, $default=false)
     {
-        self::setup();
-        $kolab  = Kolab_List::singleton();
+        $kolab = self::get_folders_list();
 
         $folder = new Kolab_Folder();
         $folder->setList($kolab);
@@ -261,17 +286,26 @@ class rcube_kolab
      */
     public static function folder_rename($oldname, $newname)
     {
-        self::setup();
-        $kolab  = Kolab_List::singleton();
+        $kolab = self::get_folders_list();
 
         $folder = $kolab->getFolder($oldname);
         $folder->setFolder($newname);
+
+        // We're not using $folder->save() because some caching issues
         $result = $kolab->rename($folder);
 
         if (is_a($result, 'PEAR_Error')) {
             return false;
         }
 
+        // need to re-set some properties
+        $folder->name     = $folder->new_name;
+        $folder->new_name = null;
+        $folder->_title   = null;
+        $folder->_owner   = null;
+        // resetting _data prevents from some wierd cache unserialization issue
+        $folder->_data    = null;
+
         return true;
     }