Index: application/functions.php
===================================================================
--- application/functions.php	(revision 49)
+++ application/functions.php	(working copy)
@@ -110,7 +110,7 @@
       } elseif (function_exists('active_project') && (active_project() instanceof Project)) {
         $active_project = active_project()->getId();
       }
-      if (trim($active_project) <> '') {
+      if (isset($active_project) && trim($active_project) <> '') {
         if (!CLEAN_URL) {
           $url_params[] = 'active_project=' . $active_project;
         } else {