I was able to successfully register, and verify, a new account
on your forums.
The only reason a registration would appear to go through, but be denied, would be if a user was found in the Stop Forum Spam database and you had the "Spam Protection Level" setting set to "Auto with Silent Fail". Though, this shouldn't be the case if you're able to login on versions 7.6+ (when SFS was added to the login system).
