i haven't noticed that, my keyboard light times out after some 30 seconds and is only lit when the screen is "up"
The button you want is that for "its sunny i don't need backlight on my keyboard "?

And a side note:
What do you guys think of the design?
if you have any custom design for this mod i can make it so that it will work, you just submit the design/look
im not the best designer at all.....