diff --git a/calendar/inc/class.calendar_ical.inc.php b/calendar/inc/class.calendar_ical.inc.php
index f41389e841..3bd314fa25 100644
--- a/calendar/inc/class.calendar_ical.inc.php
+++ b/calendar/inc/class.calendar_ical.inc.php
@@ -615,6 +615,8 @@ class calendar_ical extends calendar_boupdate
 						$rrule = $rriter->generate_rrule($version);
 						if ($event['recur_enddate'])
 						{
+							$length = $event['end'] - $event['start'];
+							$rrule['UNTIL']->modify($length . ' second');
 							if (!$tzid || $version != '1.0')
 							{
 								if (!isset(self::$tz_cache['UTC']))
@@ -1052,6 +1054,7 @@ class calendar_ical extends calendar_boupdate
 	function importVCal($_vcalData, $cal_id=-1, $etag=null, $merge=false, $recur_date=0, $principalURL='', $user=null, $charset=null)
 	{
 		$this->events_imported = 0;
+		$replace = $delete_exceptions= false;
 
 		if (!is_array($this->supportedFields)) $this->setSupportedFields();
 
@@ -1065,6 +1068,7 @@ class calendar_ical extends calendar_boupdate
 		{
 			if (count($events) == 1)
 			{
+				$replace = $recur_date == 0;
 				$events[0]['id'] = $cal_id;
 				if (!is_null($etag)) $events[0]['etag'] = (int) $etag;
 				if ($recur_date) $events[0]['recurrence'] = $recur_date;
@@ -1120,43 +1124,42 @@ class calendar_ical extends calendar_boupdate
 					. array2string($event)."\n",3,$this->logfile);
 			}
 
-			/*
-			if ($event['recur_type'] != MCAL_RECUR_NONE)
+			$updated_id = false;
+			
+			if ($replace)
 			{
-				// Adjust the event start -- no exceptions before and at the start
-				$length = $event['end'] - $event['start'];
-				$rriter = calendar_rrule::event2rrule($event, false);
-				$rriter->rewind();
-				if (!$rriter->valid()) continue; // completely disolved into exceptions
-
-				$newstart = egw_time::to($rriter->current, 'server');
-				if ($newstart != $event['start'])
+				$event_info['type'] = $event['recur_type'] == MCAL_RECUR_NONE ?
+					'SINGLE' : 'SERIES-MASTER';
+				$event_info['acl_edit'] = $this->check_perms(EGW_ACL_EDIT, $cal_id);
+				if (($event_info['stored_event'] = $this->read($cal_id, 0, false, 'server')) &&
+					$event_info['stored_event']['recur_type'] != MCAL_RECUR_NONE &&
+					($event_info['stored_event']['recur_type'] != $event['recur_type']
+					|| $event_info['stored_event']['recur_interval'] != $event['recur_interval']
+					|| $event_info['stored_event']['recur_data'] != $event['recur_data']
+					|| $event_info['stored_event']['start'] != $event['start']))
 				{
-					// leading exceptions skiped
-					$event['start'] = $newstart;
-					$event['end'] = $newstart + $length;
-				}
-
-				$exceptions = $event['recur_exception'];
-				foreach($exceptions as $key => $day)
-				{
-					// remove leading exceptions
-					if ($day <= $event['start'])
+					// handle the old exceptions
+					$recur_exceptions = $this->so->get_related($event_info['stored_event']['uid']);
+					foreach ($recur_exceptions as $id)
 					{
-						if ($this->log)
+						if ($delete_exceptions)
 						{
-							error_log(__FILE__.'['.__LINE__.'] '.__METHOD__.
-								'(): event SERIES-MASTER skip leading exception ' .
-								$day . "\n",3,$this->logfile);
+							$this->delete($id);
+						}
+						else
+						{
+							if (!($exception = $this->read($id))) continue;
+							$exception['uid'] = common::generate_uid('calendar', $id);
+							$exception['reference'] = $exception['recurrence'] = 0;
+							$this->update($exception, true);
 						}
-						unset($exceptions[$key]);
 					}
 				}
-				$event['recur_exception'] = $exceptions;
 			}
-			*/
-			$updated_id = false;
-			$event_info = $this->get_event_info($event);
+			else
+			{
+				$event_info = $this->get_event_info($event);
+			}
 
 			// common adjustments for existing events
 			if (is_array($event_info['stored_event']))
@@ -1471,55 +1474,7 @@ class calendar_ical extends calendar_boupdate
 						if (is_array($days))
 						{
 							$recur_exceptions = array();
-							/*
-							if (!isset($days[$event_info['stored_event']['start']]) &&
-								$event_info['stored_event']['start'] < $event['start'])
-							{
-								// We started with a pseudo exception and moved the
-								// event start therefore to the future; let's try to go back
-								$exceptions = $this->so->get_recurrence_exceptions($event_info['stored_event'], $this->tzid, 0, 0, 'rrule');
-								if ($this->log)
-								{
-									error_log(__FILE__.'['.__LINE__.'] '.__METHOD__."(START ADJUSTMENT):\n" .
-										array2string($exceptions)."\n",3,$this->logfile);
-								}
-								$startdate = $event_info['stored_event']['start'];
-								$length = $event['end'] - $event['start'];
-								$rriter = calendar_rrule::event2rrule($event_info['stored_event'], false);
-								$rriter->rewind();
-								do
-								{
-									// start is a pseudo excpetion for sure
-									$rriter->next_no_exception();
-									$day = $this->date2ts($rriter->current());
-									if ($this->log)
-									{
-										error_log(__FILE__.'['.__LINE__.'] '.__METHOD__.
-											'(): event SERIES-MASTER try leading pseudo exception ' .
-											$day . "\n",3,$this->logfile);
-									}
-									if ($day >= $event['start']) break;
-									if (!isset($exceptions[$day]))
-									{
-										// all leading occurrences have to be exceptions;
-										// if not -> no restore
-										if ($this->log)
-										{
-											error_log(__FILE__.'['.__LINE__.'] '.__METHOD__.
-												'(): event SERIES-MASTER pseudo exception series broken at ' .
-												$rriter->current() . "!\n",3,$this->logfile);
-										}
-										$startdate = $event['start'];
-										$recur_exceptions = array();
-										break;
-									}
-									$recur_exceptions[] = $day;
-								} while ($rriter->valid());
-
-								$event['start'] = $startdate;
-								$event['end'] = $startdate + $length;
-							} */
-
+							
 							foreach ($event['recur_exception'] as $recur_exception)
 							{
 								if (isset($days[$recur_exception]))
@@ -1592,43 +1547,7 @@ class calendar_ical extends calendar_boupdate
 									array_unique(array_merge($event_info['master_event']['recur_exception'],
 										array($event['recurrence'])));
 							}
-							/*
-							// Adjust the event start -- must not be an exception
-							$length = $event_info['master_event']['end'] - $event_info['master_event']['start'];
-							$rriter = calendar_rrule::event2rrule($event_info['master_event'], false);
-							$rriter->rewind();
-							if ($rriter->valid())
-							{
-								$newstart = egw_time::to($rriter->current, 'server');
-								foreach($event_info['master_event']['recur_exception'] as $key => $day)
-								{
-									// remove leading exceptions
-									if ($day < $newstart)
-									{
-										if (($foundEvents = $this->find_event(
-											array('uid' => $event_info['master_event']['uid'],
-												'recurrence' => $day), 'exact')) &&
-												($eventId = array_shift($foundEvents)) &&
-												($exception = read($eventId, 0, 'server')))
-										{
-											// Unlink this exception
-											unset($exception['uid']);
-											$this->update($exception, true);
-										}
-										if ($event['recurrence'] == $day)
-										{
-											// Unlink this exception
-											unset($event['uid']);
-										}
-										unset($event_info['master_event']['recur_exception'][$key]);
-									}
-								}
-							}
-							if ($event_info['master_event']['start'] < $newstart)
-							{
-								$event_info['master_event']['start'] = $newstart;
-								$event_info['master_event']['end'] = $newstart + $length;
-							}*/
+							
 							$event['reference'] = $event_info['master_event']['id'];
 							$event['category'] = $event_info['master_event']['category'];
 							$event['owner'] = $event_info['master_event']['owner'];
diff --git a/calendar/inc/class.calendar_so.inc.php b/calendar/inc/class.calendar_so.inc.php
index 9bc7bce4ba..5b0fe85e32 100644
--- a/calendar/inc/class.calendar_so.inc.php
+++ b/calendar/inc/class.calendar_so.inc.php
@@ -914,8 +914,23 @@ ORDER BY cal_user_type, cal_usre_id
 			$this->db->update($this->cal_table, array('cal_uid' => $event['cal_uid']),
 				array('cal_id' => $event['cal_id']),__LINE__,__FILE__,'calendar');
 		}
-		// write information about recuring event, if recur_type is present in the array
-		if ($event['recur_type'] != MCAL_RECUR_NONE)
+		
+		if ($event['recur_type'] == MCAL_RECUR_NONE)
+		{
+			$this->db->delete($this->dates_table,array(
+				'cal_id' => $cal_id),
+				__LINE__,__FILE__,'calendar');
+			
+			// delete all user-records, with recur-date != 0
+			$this->db->delete($this->user_table,array(
+				'cal_id' => $cal_id, 'cal_recur_date != 0'),
+				__LINE__,__FILE__,'calendar');
+			
+			$this->db->delete($this->repeats_table,array(
+				'cal_id' => $cal_id),
+				__LINE__,__FILE__,'calendar');
+		}
+		else // write information about recuring event, if recur_type is present in the array
 		{
 			// fetch information about the currently saved (old) event
 			$old_min = (int) $this->db->select($this->dates_table,'MIN(cal_start)',array('cal_id'=>$cal_id),__LINE__,__FILE__,false,'','calendar')->fetchColumn();
@@ -1024,14 +1039,7 @@ ORDER BY cal_user_type, cal_usre_id
 			// write the repeats table
 			$event['recur_exception'] = empty($event['recur_exception']) ? null : implode(',',$event['recur_exception']);
 			unset($event[0]);	// unset the 'etag=etag+1', as it's not in the repeats table
-			if($event['recur_type'] != MCAL_RECUR_NONE)
-			{
-				$this->db->insert($this->repeats_table,$event,array('cal_id' => $cal_id),__LINE__,__FILE__,'calendar');
-			}
-			else
-			{
-				$this->db->delete($this->repeats_table,array('cal_id' => $cal_id),__LINE__,__FILE__,'calendar');
-			}
+			$this->db->insert($this->repeats_table,$event,array('cal_id' => $cal_id),__LINE__,__FILE__,'calendar');
 		}
 		// update start- and endtime if present in the event-array, evtl. we need to move all recurrences
 		if (isset($event['cal_start']) && isset($event['cal_end']))