Keyboard Backlighting Problem

Question

Hello,
Recently, if i use the f5 or f6 keys to raise or lower the level of illumination on my laptops keyboard, the semi-transparent window comes up with the horizontal bar and the blocks to indicate brightness level, but has a O with a slash through it underneath the row of blocks, and neither keys have any effect.
I went to system preferences, enabled "illuminate keyboard in low light conditions" and it lit right up. I then tried to use the keys once it was already lit in this manner, and they functioned RIGHT until I uncovered the iSight camera (I covered it to cut off all light).
Any help?
Thanks in advance, and Happy Holidays!

Answer 1

Just to add to eww's observations, it seems to me that the location of the sensor in the upper bezel next to the iSight camera adds to the problems quite a bit. I find myself that the light falling on this point can be quite different from that falling on the keyboard itself. Simply changing the angle of the screen, or altering ones sitting position can produce substantial variations in the behaviour of the backlight. We have high "clerestory" windows in our house for example, and if I sit with my back to them the light hitting the light sensor can be far greater than the light falling on the keyboard itself.
I can see pluses in the location , too, especially on a small keyboard like the 13" one where ones hands would be likely to interefere with illumination levels, but by and large I think the location on the early MBPs under the speaker grids on either side of the keyboard was superior.
Maybe rather than using "blackout" tape, some sort of semi transparent filter material over the sensor would be an option?
Cheers
Rod