Index: trunk/core/units/categories/categories_event_handler.php
===================================================================
diff -u -N -r8491 -r8562
--- trunk/core/units/categories/categories_event_handler.php	(.../categories_event_handler.php)	(revision 8491)
+++ trunk/core/units/categories/categories_event_handler.php	(.../categories_event_handler.php)	(revision 8562)
@@ -141,9 +141,15 @@
 
 		if ("$parent_cat_id" != 'any') {
 			if ($event->getEventParam('recursive')) {
-				$current_path = $this->Conn->GetOne('SELECT ParentPath FROM '.TABLE_PREFIX.'Category WHERE CategoryId='.$parent_cat_id);
-				$subcats = $this->Conn->GetCol('SELECT CategoryId FROM '.TABLE_PREFIX.'Category WHERE ParentPath LIKE "'.$current_path.'%" ');
-				$object->addFilter('parent_filter', 'ParentId IN ('.implode(', ', $subcats).')');
+				if ($parent_cat_id > 0) {
+					// not "Home" category
+					$sql = 'SELECT TreeLeft, TreeRight
+							FROM '.TABLE_PREFIX.'Category
+							WHERE CategoryId = '.$parent_cat_id;
+					$tree_indexes = $this->Conn->GetRow($sql);
+
+					$object->addFilter('parent_filter', TABLE_PREFIX.'Category.TreeLeft BETWEEN '.$tree_indexes['TreeLeft'].' AND '.$tree_indexes['TreeRight']);
+				}
 			}
 			else {
 				$object->addFilter('parent_filter', 'ParentId = '.$parent_cat_id);