VirtueMart has a nasty little bug some people may have noticed relating to the shopping cart. For some reason, the cart loses its proper Itemid and reverts to whatever Itemid is associated with the Home page. This issue has hounded me for a while, and I've tried to create templates that are able to handle this problem rathar than solve it. However, I have a simple solution that appears to work.
FILE: administrator/com_virtuemart/html/checkout.index.php
LINE: 96
REPLACE
if ($perm->is_registered_customer($auth['user_id'])) { // user is logged in and a registered customer
$basket_html .= '<form action="'. SECUREURL.basename($_SERVER['PHP_SELF']) .'" method="post" name="adminForm">'