Index: trunk/core/units/categories/categories_item.php
===================================================================
diff -u -r3787 -r4243
--- trunk/core/units/categories/categories_item.php	(.../categories_item.php)	(revision 3787)
+++ trunk/core/units/categories/categories_item.php	(.../categories_item.php)	(revision 4243)
@@ -55,7 +55,7 @@
 
 			$sql = 'SELECT ParentPath FROM '.$cat_table.' WHERE CategoryId = %s';
 			$parent_path = $this->Conn->GetOne( sprintf($sql, $parent_id) );
-			if(!$parent_path) $parent_path = '|'.$parent_id.'|';
+			if(!$parent_path && $parent_id) $parent_path = '|'.$parent_id.'|';
 
 			return $parent_path.$this->GetID().'|';
 		}