It's the only thing I can figure that happened, but here's a copy of what I sent EA incase anybody has had the same problem....
I recently got a second hard drive, and set up a RAID 0 array to put my games on. After uninstaling both BF2 and BF2:SF, I re-installed BF2 on the new array, and turned off my computer after playing for an hour or so. Today, I went to re-install Special Forces, and the installer kept crashing. I finaly got the game to install, but now when I play online I recive a message that my "CD key is either invalid or in already in use". I didn't get this error with BF2, and they were both uninstalled the same way at the same time. I know the key is not in use anymore, because I have run CCleaner to clean up any leftover registry entries, and done a second re-install of Special Forces, but the error still persists, only in SF, not regular BF2. I registered the game, and it gave me the error, but I re-typed the cd key the registration program took it, but the game still dosn't allow me to play. If it helps, my proof of purchase number is: *******
Any idea's what's going on?