Installed Vista RC1 recently, and even got my Audigy 2ZS to work without turning off driver signing (don't ask me how, dunno), but it reboots randomly. Reboot can be in five minutes, or two hours, completely random. I may be dragging a window, playing UT, opening a gadget, or the PC may be left by itself. When Vista restarts, it tells me that the video card driver had a problem. Had the problem with the default ATI drivers in Vista, and the latest RC1 drivers. Card is Radeon 9500. Anybody else had a similar problem? Any suggestions?