--- common.inc.orig	2010-12-16 04:11:22.000000000 +0700
+++ common.inc	2011-01-01 10:03:45.000000000 +0700
@@ -2701,7 +2701,8 @@ function page_set_cache() {
         $data = gzencode($data, 9, FORCE_GZIP);
       }
       ob_end_flush();
-      cache_set($base_root . request_uri(), $data, 'cache_page', CACHE_TEMPORARY, drupal_get_headers());
+      //cache_set($base_root . request_uri(), $data, 'cache_page', CACHE_TEMPORARY, drupal_get_headers());
+      cache_set($base_root . urldecode(request_uri()), $data, 'cache_page', CACHE_TEMPORARY, drupal_get_headers());
     }
   }
 }