--- includes/common.inc.orig	2008-05-10 13:01:15.000000000 +0200
+++ includes/common.inc	2008-05-10 12:58:43.000000000 +0200
@@ -1435,7 +1435,7 @@
     );
 
   // Append active class.
-  if ($path == $_GET['q'] || ($path == '<front>' && drupal_is_front_page())) {
+  if (url($path, $options) == url($_GET['q']) || ($path == '<front>' && drupal_is_front_page())) {
     if (isset($options['attributes']['class'])) {
       $options['attributes']['class'] .= ' active';
     }
--- includes/theme.inc.orig	2008-05-10 13:01:27.000000000 +0200
+++ includes/theme.inc	2008-05-10 12:59:39.000000000 +0200
@@ -1112,7 +1112,7 @@
       if ($i == $num_links) {
         $class .= ' last';
       }
-      if (isset($link['href']) && ($link['href'] == $_GET['q'] || ($link['href'] == '<front>' && drupal_is_front_page()))) {
+      if (isset($link['href']) && (url($link['href'], $link) == url($_GET['q']) || ($link['href'] == '<front>' && drupal_is_front_page()))) {
         $class .= ' active';
       }
       $output .= '<li class="'. $class .'">';