Index: sites/all/modules/contrib/drupalvb/drupalvb.inc.php
===================================================================
--- sites/all/modules/contrib/drupalvb/drupalvb.inc.php	(revision 600)
+++ sites/all/modules/contrib/drupalvb/drupalvb.inc.php	(working copy)
@@ -66,7 +66,7 @@
 
   $cookie_prefix = (isset($vb_config['Misc']['cookieprefix']) ? $vb_config['Misc']['cookieprefix'] : 'bb');
   $cookie_path = $vb_options['cookiepath'];
-  $cookie_domain = $vb_options['cookiedomain'];
+  $cookie_domain = (!empty($vb_options['cookiedomain']) ? $vb_options['cookiedomain'] : $GLOBALS['cookie_domain']);
   $expire = time() - 86400;
   
   if (!empty($userid)) {