To get it working, I added: Option "MonitorLayout" "LVDS" Works with or without 'radeon' kernel module. When I quit X, I get the blooming effect. If I then restart X, I get the weird glitches that I was getting with a Modeline that was slightly off: Modeline "1280x854" 80 1280 1309 1460 1636 854 857 864 896 +HSync +VSync I reboot, then it works fine again. ------------------------------------------------------------------------ Previously, even tho everything seemed to work fine, I was getting this error: radeonfb: Failed to detect DFP panel size Using unsupported 1280x854 ATY,Crown_A at bc008000, depth=8, pitch=1280 People on the debian list told me that it was a hardware problem. I have since have had my motherboard replaced, and low and behold, the problem went away: radeonfb: detected DFP panel size from EDID: 1280x854 ------------------------------------------------------------------------