When I use my laptop with very low brightness (lower than the setted-up powersaving level) and the power saving module activetes, it increases the brightness. 

I'm using XFCE 4.8.3 on Arch and xfce4-power-manager 1.0.10.

This could be solved with adding a single line like this:
if (current_brightness>powersave_brightness){
<current code>
}

Regards,
Gergő