diff --git a/calendar/inc/class.calendar_bo.inc.php b/calendar/inc/class.calendar_bo.inc.php
index 8e23eec953..f2111ae473 100644
--- a/calendar/inc/class.calendar_bo.inc.php
+++ b/calendar/inc/class.calendar_bo.inc.php
@@ -2059,7 +2059,6 @@ class calendar_bo
 		if (!is_array($entry))
 		{
 			list($id,$recur_date) = explode(':',$entry);
-			if (!$this->check_perms(EGW_ACL_FREEBUSY, $id, 0, 'server')) return false;
 			$entry = $this->read($id, $recur_date, true, 'server');
 		}
 		$etag = $schedule_tag = $entry['id'].':'.$entry['etag'];
diff --git a/calendar/inc/class.calendar_groupdav.inc.php b/calendar/inc/class.calendar_groupdav.inc.php
index a4db000e09..9327ccec55 100644
--- a/calendar/inc/class.calendar_groupdav.inc.php
+++ b/calendar/inc/class.calendar_groupdav.inc.php
@@ -842,7 +842,9 @@ class calendar_groupdav extends groupdav_handler
 			{
 				$user_and_memberships = $GLOBALS['egw']->accounts->memberships($user, true);
 				$user_and_memberships[] = $user;
-				if (!array_intersect(array_keys($oldEvent['participants']), $user_and_memberships))
+				if (!array_intersect(array_keys($oldEvent['participants']), $user_and_memberships) &&
+					// above can be true, if current user is not in master but just a recurrence
+					(!$oldEvent['recur_type'] || !($series = self::get_series($oldEvent['uid'], $this->bo))))
 				{
 					if ($this->debug) error_log(__METHOD__."(,,$user) user $user is NOT an attendee!");
 					return '403 Forbidden';
@@ -851,11 +853,10 @@ class calendar_groupdav extends groupdav_handler
 				if (($events = $handler->icaltoegw($vCalendar)))
 				{
 					$modified = 0;
-					$series = null;
 					foreach($events as $n => $event)
 					{
 						// for recurrances of event series, we need to read correct recurrence (or if series master is no first event)
-						if ($event['recurrence'] || $n && !$event['recurrence'])
+						if ($event['recurrence'] || $n && !$event['recurrence'] || isset($series))
 						{
 							// first try reading (virtual and real) exceptions
 							if (!isset($series))
@@ -868,7 +869,7 @@ class calendar_groupdav extends groupdav_handler
 								if ($oldEvent['recurrence'] == $event['recurrence']) break;
 							}
 							// if no exception found, check if it might be just a recurrence (no exception)
-							if ($oldEvent['recurrence'] != $event['recurrence'])
+							if ($event['recurrence'] && $oldEvent['recurrence'] != $event['recurrence'])
 							{
 								if (!($oldEvent = $this->bo->read($eventId, $event['recurrence'], true)) ||
 									// virtual exceptions have recurrence=0 and recur_date=recurrence (series master or real exceptions have recurence=0)