[ubuntu] Sporadic delay in brightness controls

view story

http://ubuntuforums.org – Hello everybody, My laptop is a Sony Vaio S13 laptop with a Nvidia 310M graphics card. Ever since I installed Ubuntu on it (11.10, now running 12.04) I have been having a recurring problem with the brightness controls. Besides the need to edit /etc/X11/xorg.conf and adding EnableBrightnessControl=1, some times brightness controls are very laggy and unresposive (needs 2 or more key strokes to respond). This really gets on my nerves as it is difficult to get a specific brightness level. I've found a workaround that consists in generating a new xorg.conf file with nvidia-xconfig, re-adding (Hardware)