So you have two keys from steam, registered on two different steam accounts?
Whatever your account on steam is should not really matter I would think, as long as you register both your keys, if you indeed have two, to the same account.
If you have several accounts on steam, you probably need several copies of the game too, you can't share one game between accounts, as far as I know.. if that's going on, then I wouldn't be surprised there are issues with the activation and such.
If I'm barking up the wrong tree, please elaborate further.