After upgrading to Ubuntu 11.10 in my Sony Vaio Laptop(VGN-CS) and using Unity as a desktop environment,increasing and decreasing brightness via fn+f5 and fn+f6 does not worked any more.
I remember that i did not installed any NVIDIA driver in my laptop,
but it seems that Ubunut itself installed it in new version after upgrading to 11.10.
I also test http://ubuntuguide.net/change-screen...ntu-11-0410-10,but it does not work.
I can not worked with my laptop any more because brightness of my
screen is too high now.