If the maximum keyboard brightness level is less than 5, the keyboard brightness up/down buttons will not change the brightness. On my particular setup, my keyboard has 4 brightness levels (0 to 3).
Created attachment 5516 Use a reasonable step value for keyboard brightness You can also see this patch at this git commit on github: https://github.com/simonsonc/xfce4-power-manager/commit/0c07f52289f17cc9e9d071e678be411613d0d6b8
I would be helpful if some people with keyboard brightness controls could test this as well. I just have the one computer with keyboard brightness.
It looks good and to avoid this patch getting forgotten, pushed to master for additional testing in: http://git.xfce.org/xfce/xfce4-power-manager/commit/?id=eec71db49f61b7c68dd11ab2b078d9d20d0241be Thanks again!
Marking resolved (before Simon yells at me for not closing fixed bug reports), thanks again for the patch!