diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index f2020121..ddaa4273 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -1919,6 +1919,8 @@ class calendar extends rcube_plugin
   public function itip_attend_response($p)
   {
     if ($p['action'] == 'attend') {
+      $this->ui->init();
+
       $this->rc->output->set_env('task', 'calendar');  // override some env vars
       $this->rc->output->set_env('refresh_interval', 0);
       $this->rc->output->set_pagetitle($this->gettext('calendar'));
diff --git a/plugins/calendar/skins/larry/calendar.css b/plugins/calendar/skins/larry/calendar.css
index 71f039f1..47460030 100644
--- a/plugins/calendar/skins/larry/calendar.css
+++ b/plugins/calendar/skins/larry/calendar.css
@@ -1444,6 +1444,7 @@ div.calendar-invitebox .rsvp-status.tentative {
 
 .calendaritipattend .centerbox {
 	width: 40em;
+	min-height: 7em;
 	margin: 80px auto 0 auto;
 	padding: 10px 10px 10px 90px;
 	background: url(images/invitation.png) 10px 10px no-repeat #fff;