Hmm yes, I believe this is a bug. This should fix it for you, please confirm:
Find this line in vbbridge.php:
Code:
if ( (!preg_match('#wp-admin#', $_POST['redirect_to']) and !defined('WP_ADMIN') and !defined('XMLRPC_REQUEST') and !$_GET['preview']) or defined('USE_ADMINCP_BRIDGE')):
Change to:
Code:
if ( (!preg_match('#wp-admin#', $_POST['redirect_to']) and !defined('WP_ADMIN') and !defined('XMLRPC_REQUEST') and !$_GET['preview'] and !$install) or (defined('USE_ADMINCP_BRIDGE') and !$install)):