I finally managed to get it working by activating the screensaver, setting it to 1 minute as the timeout of screen backlight. Maybe there is an issue when screensaver is not turned on.
-- Karmic upgrade not shutting off backlight after time https://bugs.launchpad.net/bugs/413168 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