Comment 28 for bug 527157

Dmitriy: Yes it is a dirty hack :) I don't know of any other applications that would increment the backlight up and down, and GNOME's ability to set the brightness to a specific percentage (without going through steps inbetween) *should* still be functional with it...although even the unpatched gnome-settings-daemon in Debian Wheezy doesn't know how to handle simple things like "dim on battery power" correctly yet so I can't test that conclusively right now.

I think that your solution might require a patch to the kernel itself. At least in my case, backlight keypresses are handled by the thinkpad-acpi module, and I'm guessing non-thinkpad problem laptops use the kernel's built-in acpi functionality. I could be wrong though.

Either way, this bug now belongs to gnome-settings-daemon, since all power-handling functionality has moved over there. This bug entry should probably be marked 'Invalid' as you said, and a new bug should be opened.