Comment 13 for bug 295251

same problem here.
i first through it may be an acpi problem, because when i add "acpi=off" in grub, the brightness worked

after some search i found out that the keys were not mapped, so i did a
setkeycodes e008 225
setkeycodes e009 224

in console (CTRL+ F1-F6) it work normaly
but in graphical mode it bugs with two problems

first : brightness go to 0% or 100% even if i release the key
second : the keyboard won't react any more... i needed to switch back in console mode (CTRL ALT F1) and to come back in X (ALT F7) to have a working keyboard again

funnyly when i press the up key just after setting the brightness, well it stop increasing or decreasing brightness, like the release code is given...