Index: background_process.module
===================================================================
--- background_process.module	(revision 13357)
+++ background_process.module	(working copy)
@@ -324,7 +324,7 @@
     return;
   }
   // Don't determine on check-token page, to avoid infinite loop
-  if ($_GET['q'] == 'background-process/check-token') {
+  if (strpos($_GET['q'], 'background-process/check-token') === 0) {
     return;
   }
   // Only determine when installation of site is finished