Why doesn't "continue" after reviewing payment information work?

I'm a somewhat disgruntled Mac owner trying to purchase an album through iTunes.

1. iTunes Apple ID login successful.
2. iTunes tells me to "review account information". Everything is entered correctly (and re-checked approx. 1,723 times).
3. I press CONTINUE, which only causes iTunes to reload the same "review account information" page after a couple of seconds (while it says "accessing iTunes store..." at the top).

Usually I'd suspect the information I put in was somehow incorrect, prompting a red marker saying "you missed a spot", but no such correction occurs and I really have checked and re-checked the information. The same information works perfectly at all other online stores.

What am I doing wrong/what is iTunes doing wrong? Thanks.