Create a new account with a new email address. I've tested it so far and it works and I was able to redeem my limited edition code as well.
Yeah I don't know why this happened, but it seems that when people made their original account when the demo was released, the servers did not save the information correctly. This is my only good guess.
Either Way this does work. So for those who can't wait for Crytex or EA fix their stupid login issue should just make a new account with a new email address. This really svcks....oh well....