BF2S Forums CD-key invalid for Special Forces.

I recently reinstalled BF2 and BF2:sf. BF2 is working fine but today I wanted to play some SF. SF has always worked before but now I got the message that the CD-key was invalid. So I closed the game and ran the Battlefield 2 Special Forces_code.exe program, reentered the SF CD-key and finally ran the 1.3 patch but I still get the same message.

Can someone please tell me what to do because I don't have a clue.

Thanks.