Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 8656)
+++ wp-includes/post.php	(working copy)
@@ -3000,7 +3000,7 @@
 		return false;
 
 	if ( !is_array($post_ids) ) {
-		$post_ids = preg_replace('|[^0-9,]|', '', $post_ids);
+		$post_ids = preg_replace('|[^0-9,-]|', '', $post_ids);
 		$post_ids = explode(',', $post_ids);
 	}