That might have something to do with it. I'm not familiar with the link given, but it sounds like there might be something wrong with the email. You could try changing the email address, and have the site re-send your activation code if necessary.
Did you wait too long to activate your account? Even if the Registration was open, sometimes waiting too long to activate it can cause problems. You could also try re-installing the game, in case it has something to do with the server.