Under 9.04 I had issues with being able to connect to an ad-hoc wireless network and I also had to workaround a bluetooth issue with my bluetooth mouse. Both of those issues are fixed in 9.10, but I too have the backlight changing issue along with the USB bug. The camera doesn't work either, when it did on 9.04. I was able to workaround the backlight issue by stopping gnu-power-manager. Not the best solution, but it does allow me to work without going into seizures.