Cannot register ME2 to BSN, while the game is activated via origin.

So i use the key found in origin details page and go to this website:

http://social.bioware.com/user_bw_games_register.php?task=registerform&game_id=10

and use the key to register. I tried both formats: the one without dashes and the one with dashes, and both give me "Code is not valid for game" msg.

I found several cases reported via BSN forum such as here and here. I even contacted EA live chat and natually they asked me to call BSN directly. I sned a msg to one of a moderator of BSN and no replies. Predictable.

Well in addition to the issue of unsucessful registeration, I wanna know is it really necessary to register the game before I can buy DLCs for ME2? I can assume paying to buy BPoints and get the dlcs from origin all together, but my friends tell me that I need to register the game anyway. So I am very confused. It is becasue I recall they remove the securerom drm from ME1, so maybe that's why the me2 registration follows the same path.

Hopefully anyone could help. Thanks in advance.