diff --git a/calendar/inc/class.calendar_uiforms.inc.php b/calendar/inc/class.calendar_uiforms.inc.php
index f479449d0c..53fb79784a 100644
--- a/calendar/inc/class.calendar_uiforms.inc.php
+++ b/calendar/inc/class.calendar_uiforms.inc.php
@@ -77,7 +77,9 @@ class calendar_uiforms extends calendar_ui
 	 */
 	function &default_add_event()
 	{
-		$extra_participants = $_GET['participants'] ? explode(',',$_GET['participants']) : array();
+		$extra_participants = $_GET['participants'] ? 
+			(!is_array($_GET['participants']) ? explode(',',$_GET['participants']) : $_GET['participants']) :
+			array();
 
 		// if participant is a contact, add its link title as title
 		foreach($extra_participants as $uid)
@@ -98,7 +100,7 @@ class calendar_uiforms extends calendar_ui
 			}
 			if(is_array($owner))
 			{
-				if($this->cal_prefs['default_participant'])
+				if($this->cal_prefs['default_participant'] || count($participants) === 0 && count($owner) === 1)
 				{
 					$extra_participants += $owner;
 				}
diff --git a/calendar/js/et2_widget_daycol.js b/calendar/js/et2_widget_daycol.js
index 2c123a3195..353c1c56c1 100644
--- a/calendar/js/et2_widget_daycol.js
+++ b/calendar/js/et2_widget_daycol.js
@@ -1077,7 +1077,7 @@ var et2_calendar_daycol = (function(){ "use strict"; return et2_valueWidget.exte
 					hour: _ev.target.dataset.hour || this._parent.options.day_start,
 					minute: _ev.target.dataset.minute || 0
 				};
-				if (this.options.owner != app.calendar.state.owner)
+				if (this.options.owner.toString() !== app.calendar.state.owner.toString())
 				{
 					options.owner = this.options.owner;
 				}
@@ -1096,7 +1096,7 @@ var et2_calendar_daycol = (function(){ "use strict"; return et2_valueWidget.exte
 					end: end,
 					non_blocking: true
 				}
-				if (this.options.owner != app.calendar.state.owner)
+				if (this.options.owner.toString() !== app.calendar.state.owner.toString())
 				{
 					options.owner = this.options.owner;
 				}
diff --git a/calendar/js/et2_widget_timegrid.js b/calendar/js/et2_widget_timegrid.js
index c166a487ec..a1af5d8c12 100644
--- a/calendar/js/et2_widget_timegrid.js
+++ b/calendar/js/et2_widget_timegrid.js
@@ -1861,7 +1861,7 @@ var et2_calendar_timegrid = (function(){ "use strict"; return et2_calendar_view.
 				hour: target.dataset.hour || this._parent.options.day_start,
 				minute: target.dataset.minute || 0
 			};
-			if (this.options.owner != app.calendar.state.owner)
+			if (this.options.owner.toString() !== app.calendar.state.owner.toString())
 			{
 				options.owner = this.options.owner;
 			}