Index: branches/unlabeled/unlabeled-1.21.4/core/kernel/db/dblist.php
===================================================================
diff -u -r7072 -r7368
--- branches/unlabeled/unlabeled-1.21.4/core/kernel/db/dblist.php	(.../dblist.php)	(revision 7072)
+++ branches/unlabeled/unlabeled-1.21.4/core/kernel/db/dblist.php	(.../dblist.php)	(revision 7368)
@@ -639,7 +639,7 @@
 	function GetDBField($name)
 	{
 		$row =& $this->getCurrentRecord();
-		
+
 		return $row[$name];
 	}
 
@@ -653,7 +653,7 @@
 	{
 		return $this->Queried ? $this->GetDBField($this->IDField) : null;
 	}
-	
+
 	/**
 	 * Allows kDBTagProcessor.SectionTitle to detect if it's editing or new item creation
 	 *
@@ -664,7 +664,7 @@
 		// no such thing as NewItem for lists :)
 		return false;
 	}
-	
+
 	function HasField($name)
 	{
 		$row =& $this->getCurrentRecord();
@@ -819,6 +819,8 @@
 			$parent_object =& $this->Application->recallObject($parent_prefix.'.'.$special);
 			$parent_id = $parent_object->GetDBField($parent_table_key);
 
+			if (!$parent_id) return ;
+
 			$this->addFilter('parent_filter', '`'.$this->TableName.'`.`'.$foreign_key_field.'` = '.$parent_id);	// only for list in this case
 		}
 	}