If your friend did not activate the account while the Registration was open, this could be causing the issue. Usually it's best to activate the account as soon as possible after creating the account. As Feareh mentioned above, what he could do is to wait until the Registration opens up again, then click on the link to activate the account. If he waits too long to do so, however, the server may delete the request to activate the account, so I would try keeping a close eye on the Registration and activate it when you next find it open.