Index: trunk/core/units/custom_fields/custom_fields_event_handler.php
===================================================================
diff -u -N -r4029 -r4330
--- trunk/core/units/custom_fields/custom_fields_event_handler.php	(.../custom_fields_event_handler.php)	(revision 4029)
+++ trunk/core/units/custom_fields/custom_fields_event_handler.php	(.../custom_fields_event_handler.php)	(revision 4330)
@@ -25,6 +25,8 @@
 			if ($item_type) {
 				$object->addFilter('itemtype_filter', '%1$s.Type = '.$item_type);
 			}
+			
+			$object->addFilter('user_filter', '%1$s.IsSystem = 0');
 		}
 		
 		/**