This is strange. I've run 64-bit windows on my cMP 1,1 forever. I have used Bootcamp to install Windows 7 x64 on the same drive as Lion, and on its own drive. Everything worked at home. I bring it into work, and none of my windows installs will boot. Not even DVDs that are specifically mac-bootable will work. Lion works just fine, and I've reset pRAM and held down the power button to clear whatever that does. I've removed and reseated the ram cards and the video card. I've removed the optical tray completely. I've pulled all other sATA drives. The boot selector can see the CD and the windows drives, but I just get a black screen when trying to boot to them. Suggestions?