Index: includes/common.inc
--- includes/common.inc.orig	2008-04-09 23:11:44 +0200
+++ includes/common.inc	2008-06-26 20:16:16 +0200
@@ -1805,7 +1832,7 @@
   $last = '';
   while ($path != $last) {
     $last = $path;
-    $path = preg_replace('`(^|/)(?!../)([^/]+)/../`', '$1', $path);
+    $path = preg_replace('`(^|/)(?!\.\./)([^/]+)/\.\./`', '$1', $path);
   }
   return 'url('. $path .')';
 }