--- singlesignon_client.module	2011-08-18 14:25:41.380400100 +1200
+++ singlesignon_client.module	2011-08-18 14:25:33.083259600 +1200
@@ -192,7 +192,7 @@
     parse_str($data['query'], $query);
     unset($query['singlesignon_message']);
     $query = singlesignon_build_query($query);
-    $origin = $base_url . '?' . $query;
+    $origin = $base_url . request_uri(). '?' . $query;
 
     $form['#action'] = singlesignon_create_request(
         $controller,