This happened to me yesterday and I can't figure out why. I was typing away in a room that I would consider average lighting. All of the sudden, the keyboard backlighting goes out but the screen stays lit. I checked my settings - no changes and nothing seems wrong.
It wasn't until I did a battery pull that the backlight started working again.
I'm curious, and maybe concerned, since I have only had it for 2-3 weeks.
