WP-Ecommerce Individual Tax

Hi there,
I’m using wp-ecommerce, I’ve asked this question on the getshopped forums but have yet to receive a response.

I’m setting up wp-ecommerce for a client, using the tax exclusive option as per their request, however along with the regional tax which has already been set-up, and the tax exempt items, they occasionally sell books.

The book in question is taxed at 5%, however using tax exclusive I can’t apply a tax band to it, how do I apply a unique tax to a single product and have it apply the 5% tax ignoring the regional tax in canada, and of course keeping the 0% tax for the USA ?

I’d greatly appreciate any help, I’ve been wracking my brain to try fix this issue to no avail.