Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 6341)
+++ wp-includes/post.php	(working copy)
@@ -1087,6 +1087,7 @@
 		$exclude = '';
 		$meta_key = '';
 		$meta_value = '';
+		$hierarchical = false;
 		$incpages = preg_split('/[\s,]+/',$include);
 		if ( count($incpages) ) {
 			foreach ( $incpages as $incpage ) {