--- includes/bootstrap.inc.orig	2010-08-06 18:50:24.000000000 +0700
+++ includes/bootstrap.inc	2010-12-08 00:25:39.000000000 +0600
@@ -1,6 +1,17 @@
 <?php
 // $Id: bootstrap.inc,v 1.206.2.29 2010/08/06 11:50:24 goba Exp $
 
+function custom_url_rewrite_inbound(&$result, $path, $path_language) {
+  global $language;
+  if (preg_match('/^node\/(.*)/', $path, $matches)) {
+    $nid = $matches[1];
+    $node_language = db_result(db_query("SELECT language FROM {node} WHERE nid=%d", $nid));
+    if ($language->language != $node_language) {
+      //this will cause a page not found
+      $result = '';
+    }
+  }
+}
 /**
  * @file
  * Functions that need to be loaded on every Drupal request.