Index: units/helpers/user_helper.php
===================================================================
--- units/helpers/user_helper.php	(revision 15437)
+++ units/helpers/user_helper.php	(working copy)
@@ -161,7 +161,9 @@
 
 			if ($user_id != USER_ROOT) {
 				$groups = $this->Application->RecallVar('UserGroups');
-				$this->Application->Session->SetField('GroupId', reset( explode(',', $groups) ));
+				list ($first_group, ) = explode(',', $groups);
+
+				$this->Application->Session->SetField('GroupId', $first_group);
 				$this->Application->Session->SetField('GroupList', $groups);
 				$this->Application->Session->SetField('TimeZone', $object->GetDBField('TimeZone'));
 			}