Comment 12 for bug 516354

I get:

$ cat /sys/class/dmi/id/product_name
MacBook5,1

$ echo 0 | sudo tee /sys/class/backlight/nvidia_backlight/brightness
0

(nothing happens to backlight)

Removing nvidia-bl-dkms and replacing it by mbp-nvidia-bl-dkms makes the backlight controls work again

This is on a unibody mbp with a dual gpu running ubuntu karmic with the mactel and puredyne ppas