> > I am running a minimal Debian Lenny AMD64 netinst. > Graphics card is an ATI Radeon 4850 with the latest Drivers from ATI 8.10 Give the open source xf86-viedo-ati driver a try. It supports your chip. It actually is easier to set up and debug. I had problems with the proprietary ATI driver performing poorly on window redraws. All was solved when using the open source ati driver. Good luck. Amit