diff -urp drupal-7.x-dev-20081013/includes/common.inc drupal-7.x-dev-patch-for-320206/includes/common.inc
--- drupal-7.x-dev-20081013/includes/common.inc	2008-10-13 03:03:04.000000000 +0800
+++ drupal-7.x-dev-patch-for-320206/includes/common.inc	2008-10-13 09:31:35.000000000 +0800
@@ -3594,7 +3594,7 @@ function drupal_flush_all_caches() {
 function _drupal_flush_css_js() {
   $string_history = variable_get('css_js_query_string', '00000000000000000000');
   $new_character = $string_history[0];
-  $characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
+  $characters = 'abcdefghijklmnoprstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
   while (strpos($string_history, $new_character) !== FALSE) {
     $new_character = $characters[mt_rand(0, strlen($characters) - 1)];
   }