I have a Samsung netbook N150Plus (mod# NP-N150-JP02UK) on which I have just installed 11.04 but although the function key works for the screen brightness and brings up the brightness +/- animation, it does not actually change the brightness.
With power on, the screen is bright but at least I can see it (but not change it) but on battery power, the screen is so dim its almost unusable in normal daylight. I have made changes to power management to no avail. Also had the same issue when I had 10.10 installed before upgrading.
Is this a driver issue of a Linux setting problem? Any help appreciated.