I had the same thing happen to me as well.
First I looked for the upgrade page - found nothing.
Ordered the full license - error in the payment section.
Came back later (today - 06/03/2008) - tried again & got an error stating that I've already got an upgrade license (the only upgrade I had was from 2006 to 2007).
Then went & tried for the full license(again) - it went through & got an e-mail with the license within 10 mins.
Just checked my CC account for the bill & discovered a charge for the first time I tried.
There was no warning that the payment went through - no re-route via Mastercard own Secure Website & no e-mail stating that I had an attachment (the license).
So the question is - where can I get a refund...?