diff --git a/calendar/inc/class.calendar_boupdate.inc.php b/calendar/inc/class.calendar_boupdate.inc.php
index cef7a84c09..baa45912e5 100644
--- a/calendar/inc/class.calendar_boupdate.inc.php
+++ b/calendar/inc/class.calendar_boupdate.inc.php
@@ -980,7 +980,7 @@ class calendar_boupdate extends calendar_bo
 			}
 		}
 		// same with the alarms
-		if (isset($event['alarm']) && is_array($event['alarm']))
+		if (isset($event['alarm']) && is_array($event['alarm']) && isset($event['start']))
 		{
 			foreach($event['alarm'] as $id => $alarm)
 			{
@@ -989,12 +989,15 @@ class calendar_boupdate extends calendar_bo
 			}
 		}
 		// update all existing alarm times, in case alarm got moved and alarms are not include in $event
-		if ($old_event && is_array($old_event['alarm']))
+		if ($old_event && is_array($old_event['alarm']) && isset($event['start']))
 		{
-			foreach($old_event['alarm'] as $alarm)
+			foreach($old_event['alarm'] as $id => $alarm)
 			{
-				$alarm['time'] = $event['start'] - $alarm['offset'];
-				$this->so->save_alarm($event['id'],$alarm, $this->now);
+				if (!isset($event['alarm'][$id]))
+				{
+					$alarm['time'] = $event['start'] - $alarm['offset'];
+					$this->so->save_alarm($event['id'],$alarm, $this->now);
+				}
 			}
 		}
 
diff --git a/calendar/inc/class.calendar_uiforms.inc.php b/calendar/inc/class.calendar_uiforms.inc.php
index 6725c28b6e..143d87c4bb 100644
--- a/calendar/inc/class.calendar_uiforms.inc.php
+++ b/calendar/inc/class.calendar_uiforms.inc.php
@@ -557,6 +557,11 @@ class calendar_uiforms extends calendar_ui
 				$event['reference'] = $event['id'];
 				$event['recurrence'] = $content['edit_single'];
 				unset($event['id']);
+				// modifiy alarms for the exception, unsetting alarm-id to create new alarms
+				foreach($event['alarm'] as $n => &$alarm)
+				{
+					unset($alarm['id']);
+				}
 				$conflicts = $this->bo->update($event,$ignore_conflicts,true,false,true,$messages,$content['no_notifications']);
 				if (!is_array($conflicts) && $conflicts)
 				{
@@ -564,6 +569,7 @@ class calendar_uiforms extends calendar_ui
 					$recur_event = $this->bo->read($event['reference']);
 					$recur_event['recur_exception'][] = $content['edit_single'];
 					unset($recur_event['start']); unset($recur_event['end']);	// no update necessary
+					unset($recur_event['alarm']);	// unsetting alarms too, as they cant be updated without start!
 					$this->bo->update($recur_event,true);	// no conflict check here
 					unset($recur_event);
 					unset($event['edit_single']);			// if we further edit it, it's just a single event