I can't play the multiplayer because the game doesn't seem to agree with my CD key. I have tried entering the code several times with no avail.

Anybody else experiencing this issue?

I know the key works because I have registered it to EA.

Just though I would express this issue to Crytek, thanks for your time.

did you get the game on the EA download manager ??

if so find the info page where your key is and make sure you put it in uppercase with the spacers like it says after every 4th character

XXXX-XXXX-XXXX etc that is how it goes.