Sorry about that, we are working on it (long story short it seems to be a caching issue). This is only an issue if you are not logged in so an easy way to fix it is to create an account. If you prefer not to create an account just ignore the zero as the "purchased" items are still in your cart and will show up when you add another item (if you prefer add a dummy item and then remove it when you see your list of items in your cart).