Hello, I'm using a Radeon 4830 with the proprietary drivers (8.5.43 I believe, the default in Ubuntu 8.10 Intrepid).
Anyways, I have hugely annoying artifacts showing down in the lower right hand corner of my monitor, they do not show up in screenshots. Changing resolutions / refresh rates don't help. I just discovered I can make them go away by clicking "identify display" in the catalyst control center, but I must repeat this every time I start X.
Happens with the newest drivers, doesn't happen with the VESA drivers. I'm fairly certain the video card isn't borked, doesn't happen in Windows, no artifacts in intensive games like Crysis or GTAIV, COD4.