I remember someone pointing this out before - if you're having trouble registering, and your email address ends with a two-letter domain (eg. .ca, .de, .ch, .fr, etc.), I think that might be why. Try another email address (if you have one) that ends with three letters (eg. .net, .com, etc.). Hotmail and Gmail both end with .com so those will work.
I remember Inty unsuccessfully trying to fix that. I don't suppose bustin98 can do something about that?