Index: wp-admin/includes/post.php
===================================================================
--- wp-admin/includes/post.php	(revision 35423)
+++ wp-admin/includes/post.php	(working copy)
@@ -1008,7 +1008,7 @@
 		$orderby = $q['orderby'];
 	} elseif ( isset( $q['post_status'] ) && in_array( $q['post_status'], array( 'pending', 'draft' ) ) ) {
 		$orderby = 'modified';
-	} else {
+	} elseif ( isset( $post_type ) && ! is_post_type_hierarchical( $post_type ) ) {
 		$orderby = 'date';
 	}