Testing on the PayPal sandbox shows that when you add a product to the wG shopping cart and select PayPal as the payment method, it only carries over the price of the products and not the shipping cost on the PayPal website.

I had Colin double check this and he confirmed that the shipping charges were not being added to the total cost that PayPal lists at their checkout.

Colin was going to work with Paul on a fix for this and stated it was in fact a bug. boo.