diff --git a/calendar/inc/class.bocalendar.inc.php b/calendar/inc/class.bocalendar.inc.php
index a463ee86f1..164019373d 100755
--- a/calendar/inc/class.bocalendar.inc.php
+++ b/calendar/inc/class.bocalendar.inc.php
@@ -2621,7 +2621,7 @@
 			{
 				$details[$key] = $val['data'];
 			}
-			$details['participants'] = implode("\n",$details['participants']);
+			$details['participants'] = $details['participants'] ? implode("\n",$details['participants']) : '';
 
 			$details['link'] = $GLOBALS['phpgw_info']['server']['webserver_url'].'/index.php?menuaction=calendar.uicalendar.view&cal_id='.$event['id'];
 			// if url is only a path, try guessing the rest ;-)
diff --git a/calendar/inc/class.uicalendar.inc.php b/calendar/inc/class.uicalendar.inc.php
index 4d8ac1ef91..f6abfe5a23 100755
--- a/calendar/inc/class.uicalendar.inc.php
+++ b/calendar/inc/class.uicalendar.inc.php
@@ -1280,10 +1280,9 @@
 					$this->bo->set_class(True);
 				}
 				// Add participants from matrixview
-				$participants = explode(";", $GLOBALS['phpgw']->session->appsession("participants") );
-				for($_f_part=0; $_f_part<count($participants); $_f_part++)
+				foreach(explode(';',$GLOBALS['phpgw']->session->appsession("participants")) as $part)
 				{
-					$this->bo->add_attribute('participants','U',$participants[$_f_part]);
+					if ($part) $this->bo->add_attribute('participants','U',$part);
 				}
 				// Add misc
 				$this->bo->add_attribute('participants','A',$this->bo->owner);