I have the same (at least very similar) problems with a Radeon RV250 (Mobility FireGL 9000) running the latest radeon driver (xserver-xorg-video-ati 1:6.13.0-1ubuntu5). The issue obviously (I tried it only shortly and then went on to 10.04) also occured with ubuntu 9.10.
Contrary to other reports, on my machine things get even worse when I turn kernel mode setting off (Desktop background and certain application windows like firefox totally black).
I have the same (at least very similar) problems with a Radeon RV250 (Mobility FireGL 9000) running the latest radeon driver (xserver- xorg-video- ati 1:6.13.0-1ubuntu5). The issue obviously (I tried it only shortly and then went on to 10.04) also occured with ubuntu 9.10.
Contrary to other reports, on my machine things get even worse when I turn kernel mode setting off (Desktop background and certain application windows like firefox totally black).
(See also http:// ubuntuforums. org/showthread. php?p=9106012)