Strange, I have several .info domains and I have no problem. Can you post the domain name here, then we can have a look and maybe one of us can spot the problem with the domain name.
Strange - just tried again and it's accepted domain no probs. - must have been a temporary server problem as I'd tried numerous times before.
(Thanks for the 2 replies as I wouldn't have bothered trying again if I hadn't known that other people had .info names on their accounts with no problems