diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 983d136f..89cdae10 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -33,7 +33,7 @@ class calendar extends rcube_plugin
 
   public $ical;
   public $ui;
-  
+
   public $defaults = array(
     'calendar_default_view' => "agendaWeek",
     'calendar_date_format'  => "yyyy-MM-dd",
@@ -92,7 +92,7 @@ class calendar extends rcube_plugin
       $this->include_stylesheet('skins/' . $skin . '/calendar.css');
     }
 
-    if ($this->rc->task == 'calendar') {
+    if ($this->rc->task == 'calendar' && $this->rc->action != 'save-pref') {
       $this->load_driver();
 
       // load iCalendar functions
diff --git a/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php b/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
index a19baec6..feca0eb7 100644
--- a/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
+++ b/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
@@ -15,7 +15,7 @@ class rcube_kolab_contacts extends rcube_addressbook
     public $primary_key = 'ID';
     public $readonly = true;
     public $editable = false;
-    public $groups = false;
+    public $groups = true;
     public $coltypes = array(
       'name'         => array('limit' => 1),
       'firstname'    => array('limit' => 1),
@@ -133,9 +133,6 @@ class rcube_kolab_contacts extends rcube_addressbook
                 if (strpos($acl, 'a') !== false || strpos($acl, 'x') !== false)
                     $this->editable = true;
             }
-
-            if (!$this->readonly)
-                $this->groups = true;
         }
     }