I wanted to let you know the form on the registration page has a problem with the zip code field being disabled after you select the country. You can enter the zip code prior, then select country and state, but it doesn't carry over to the payment page and fills the zip code field for the payment page with the two letter state abbreviation instead of the zip code. I think it will cause problems if people don't notice it and change it prior to submitting payment.

Anyway, just a heads up.