Well, have you tried new drivers?
thread moved...why this was in OS optimization I'm not sure...
moved to LCD/Screens
While trying to fix the problem, I ended up messing up the display, so I spent most of the day fixing it in the first place. I found a thread in the faq that would have helped me, had I not made it worse.
When I had checked about a year ago, my only option was my oem driver, however since then ATI has put out a mobile version of their drivers and catalyst software, so I was able to download that. The installer wouldn't work for my configuration but I was able to install the driver and catalyst software manually, and then I was able to clone the laptop to the car LCD using the Catalyst software.
For the mobility 9000, you can use the modified drivers from Omega's site up to Catalyst 6.1 (where I think ATI dropped support for the 9000)...with his drivers, you can do custom resolutions, which is very, very useful to get a clear display on 7" Xenarcs and Lilliput's and the like (800 X 480). You might have better luck with those drivers because they have built-in support for the 9000, no "manual force" required.
I have too much time and too little aggravation in my life, so I built a carPC. ;)