I'm currently using a LG laptop with Nvidia Cuda GeForce GT 335M.
I have difficulty adjusting the screen brightness using FN+Arrow Up/Arrow Down. The brightness indicator will appear and the bar will not decrease beyond the first jump. Subsequently, if I depress the button, the indicator bar will randomly appear to be dim and bright, with no actual difference to the screen brightness.
I have tried to adjust the brightness through System Settings>Screen. Although the bar can be dragged up and down, there seems to be no actual difference in the brightness.
Furthermore, after installing Ubuntu 11.10, I have difficulty adjusting the brightness in Windows 7 as well. The function button does not respond at all, and adjusting it through the Control Panel does not seems to have any actual difference.
What could be the problem?
I have tried to edit the
/etc/X11/xorg.conf, and add the line
Option "RegistryDwords" "EnableBrightnessControl=1", but it is not working for me.