whmcs integration plugin

morning all

using this plugin and it works pretty well
few issues if anyone can help

the cart appears to be in a frame if we use the left menu in wordpress

http://vanguardsys.com/whmcs-portal?whmcsportalpage=http%3A%2F%2Fvanguardsys.com%2Fwhmcs%2Fcart.php

any ideas?