gutsy video scrolling problem

[Luca Ferrari]

Hi,
I'm using a compaq nx8430 with an ATI MObility Radeon x1600. With kubuntu 7.04 
and the ati drivers everything was ok, now, after an upgrade to gutsy it 
seems the drivers are ok, but the screen is not refreshing properly. In 
particular, a 3d screensaver runs ok, while operations such as scrolling a 
file list, or arranging windows on the screen is very very slow. What could 
be? I've checked and the restricted modules are already installed.....


Thanks,
Luca