May I ask which Folding client you are running? I was running the GUI client on WinXP, had problems with games (Battlefield 2, Red Alert 2) constantly switching back to the desktop. Turned the folding client off, games worked fine. Wished I had figured that workaround out before selling my copy of Battlefield 2.
I use the GUI client on Windows XP SP2.
Besides switching back to the desktop, I also get a pixel format error. I may switch over to the console for the gaming computers.