Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.1072
diff -u -p -r1.1072 common.inc
--- includes/common.inc	2 Jan 2010 17:39:19 -0000	1.1072
+++ includes/common.inc	3 Jan 2010 05:19:21 -0000
@@ -4373,7 +4373,7 @@ function drupal_clear_js_cache() {
  */
 function drupal_json_encode($var) {
   // json_encode() does not escape <, > and &, so we do it with str_replace().
-  return str_replace(array('<', '>', '&'), array('\x3c', '\x3e', '\x26'), json_encode($var));
+  return str_replace(array('<', '>', '&'), array('\u003c', '\u003e', '\u0026'), json_encode($var));
 }
 
 /**