Comment 4 for bug 348675

The minimum required BIOS version is 11Ca because "brightness controls require BIOS 11CA due to the new graphics system. " as seen at https://help.ubuntu.com/community/NC10#Karmic%209.10 Please note that the issue about completely enabling/disabling baclight (eg screen on/off) with Fn-F5 button is tracked at bug 296489.