Vanilla install of Ubuntu 13.10 on my MSI Wind U100. Intel graphics card I think.
Auto brightness flickers up and down, brightness hud display top-right also flickers. Interrupts input so need to restart to fix. Issue is triggered by attempting to adjust screen brightness by Fn+F4/Fn+F5, looking at the Brightness & Lock control panel in System Settings, or when laptop goes into battery saving mode (or whatever happens when the battery gets really low).
Very similar to this issue.
Issue is temporarily fixed with this code:
sudo chmod u-w /sys/class/backlight/acpi_video0/brightness
but issue returns after a restart. Prior to running this code the brightness settings do not appear in Brightness & Lock, after running this code the brightness settings appear but the brightness slider doesn't work.