I just integrated with WP ecommerce. I have each product set up with 42 variations (donation amount + size), all with the specific price and sku setup. When I click "Buy Now" on the product page, I am redirected to PayPal (with the correct PayPal account information shown), but the price shows up as $0.00 with the correct shipping of $6.00. The sku usually shows up as the page sku and not the variations sku.
Sometimes though, it shows up correctly and has the correct variation sku with it's price.
I made sure that I have only 1 version of jquery running on my site and have done the 'flush theme cache' a million times. Losing my mind over here.
Here's a link to the live site with the product.
http://www.parrotvillage.org/product/t-shirts/parrot-village-black-t-shirt/