diff --git a/calendar/inc/class.calendar_boupdate.inc.php b/calendar/inc/class.calendar_boupdate.inc.php
index b98782f5dd..cf9632a5bb 100644
--- a/calendar/inc/class.calendar_boupdate.inc.php
+++ b/calendar/inc/class.calendar_boupdate.inc.php
@@ -737,7 +737,13 @@ class calendar_boupdate extends calendar_bo
 					case 'ical':
 						if ($method == 'REQUEST')
 						{
-							$ics = ExecMethod2('calendar.calendar_ical.exportVCal',$event['id'],'2.0',$method);
+							if (is_null($ics))
+							{
+								$calendar_ical = new calendar_ical();
+								$calendar_ical->setSupportedFields('groupdav');	// full iCal fields+event TZ
+								$ics = $calendar_ical->exportVCal($event['id'],'2.0',$method);
+								unset($calendar_ical);
+							}
 							$attachment = array(	'string' => $ics,
 													'filename' => 'cal.ics',
 													'encoding' => '8bit',
diff --git a/calendar/inc/class.calendar_ical.inc.php b/calendar/inc/class.calendar_ical.inc.php
index 7c3ebc0b95..36177e22d9 100644
--- a/calendar/inc/class.calendar_ical.inc.php
+++ b/calendar/inc/class.calendar_ical.inc.php
@@ -2063,18 +2063,11 @@ class calendar_ical extends calendar_boupdate
 				break;
 
 			case 'file':	// used outside of SyncML, eg. by the calendar itself ==> all possible fields
-				if (isset($this->cal_prefs['export_timezone']))
+				if ($this->cal_prefs['export_timezone'])
 				{
-					switch ($this->cal_prefs['export_timezone'])
-					{
-						case 1:
-							$this->tzid = false; // use event's TZ
-							break;
-						default:
-							$this->tzid = $this->cal_prefs['export_timezone'];
-					}
+					$this->tzid = $this->cal_prefs['export_timezone'];
 				}
-				else
+				else	// not set or '0' = use event TZ
 				{
 					$this->tzid = false; // use event's TZ
 				}