WP eCommerce Tax Issue

We are having a tax issue on our site, yes I know we need to update our word press version and we are working on that. The issue we are having is that the tax is being applied before a discount is applied. So that means if someone has 4 products in their cart the tax is hitting the subtotal which is fine if the customer doesn’t have a discount code to use. If they have a discount code to use the taxes are calculating off the full price, not the discounted price, thus the charging too much tax.

We are using the Gold Cart plugin with our WP eCommerce. Please let me know if there is anything I can do to fix this.

Yes, I have posted this in the plugin support section as well, but the crew at WP eCommerce do not seem very responsive nor helpful and this is a time sensitive issue as we are moving to a new inventory management system and things aren’t matching up.