SIMS 3 Serial Number?

Okay , so I'm trying to register my game into the Sims 3 website so I can have an account . I already made the account now Im at the part where it says "Register A Game" . I have tried like literaly 20 different ways of putting in my code. Lowercase , all caps ..EVERYThing ! It still wont work . Yes I've made sure the the S's werent Z's or the B's weren't D's and all that !! It still wont work ! Does it matter how old it is...it really shouldnt . If I uninstall my game and put the code back in Its still going to work ! So why not now ?