Blizzcon Beta & Murloc code sumissions broken

I have recently been trying to enter the codes from my Blizzcon card. The pages to enter the codes load OK, but every time I try to submit them I get taken to: http://www.worldofwarcraft.com/errors/error.html

It's not giving me an incorrect code error or anything, its not every trying to authenticate it seems, it just instantly takes me to the error page

Are these sign-up pages broken? I hear there is an expiration date on these codes now, so when is this likely to be fixed?