Err=102 Key Code already used?

It's telling me i've already used my Key Code -- I preordered and picked up my copy today, its past 3am EST (midnight PDT) and I can't log in because it's telling me the ONE key I own is already used =/ Any ideas on where I can get the second key I might need or how to fix it so it'll accept my first one?

Are you entering the code on the little letter labeled "You're Invited", from the preorder box?

Or are you entering the retail code, which comes with the retail cd?