This is definitely odd considering some are registering just fine and others aren't. So, only thing I can say is please make sure EVERY field is filled in because they did say ALL FIELDS are required to register.

I'll tell you what, for those who keep getting the "Invalid Form Data!" error, PM me your username you signed up with and I will relay it to the staff so they can confirm your account. That's really the best I can do and I am sorry this is happening to some of you.