Index: branches/version-2_13-dev/data/class/helper/SC_Helper_Purchase.php
===================================================================
--- branches/version-2_13-dev/data/class/helper/SC_Helper_Purchase.php	(revision 23605)
+++ branches/version-2_13-dev/data/class/helper/SC_Helper_Purchase.php	(revision 23681)
@@ -71,4 +71,7 @@
         $objQuery->begin();
         if (!$objSiteSession->isPrePage()) {
+            // エラー時は、正当なページ遷移とは認めない
+            $objSiteSess->setNowPage('');
+
             SC_Utils_Ex::sfDispSiteError(PAGE_ERROR, $objSiteSession);
         }