I have to concur - I signed up for the service at the weekend and it took around 20 attempts to get the right code entered.
Hadn't received any activation emails (assumed this may be related to having a Hotmail id), so tried changing my email id, this took around another 20 attempts.
Says it's case sensitive, not sure how you're supposed to differentiate between Oo0 xX vV mM kK wW uU pP zZ etc etc etc