I have an 11" 2011 Macbook Air (the first with the backlit keyboard), now running Mountain Lion. The machine came with Snow Leopard installed, under which the automatic controls for the backlit keyboard worked perfectly. With Lion, the automatic control stopped working, no matter how you tried to reset the power management unit (or whatever that trick is to reset the thing that looks after stuff like that). With Mountain Lion, the automatic keyboard backlight is still not working. Has anyone managed to get it to work? It's not just my machine, is it? I can still control the backlight with the keyboard buttons, and the "Adjust keyboard brightness in low light" is available in keyboard preferences (and is ticked).