It seems that with new catalyst 10.5 which was released today brightness working just fine
-- Cannot adjust brightness in Lucid Lynx https://bugs.launchpad.net/bugs/555122 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-power-manager in ubuntu. -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
