iTunes: "Your account was changed while you were editing your account information."
Solution 1:
I could see a race condition causing this briefly, but if you get this error for more than 15 minutes, I would get in queue with Apple support:
- http://www.apple.com/support/ios/contact/
- http://www.apple.com/support/systemstatus
Unless there is an outage, you'll likely need someone to assist you on the sever side to resolve these errors.