Regarding forum account upgrade

I've purchased the alpha and when I attempt to register it through the link I received on the email, it tells me that I have to create a new account on the forums. Is this happening because I used two different email addresses on fastspring and the forums? If this is the case, is it possible to register it through this account?

 

i just keep getting looped, i can't upgrade my account (I used the same Email).

 

My account upgraded fine when i clicked the link but i can only view the Alpha forum, i can't post in any threads as the forum returns an error saying i dont have permission.

 

Forget about it, I figured out I could register it by changing the forum's mail address to the one I used to buy the game.