Cannot completely dim screen when f.lux is changing temperature after being disabled

[wurwur]

First of all thanks for this great piece of software! Especially my eyes are quite grateful.

I have f.lux disabled for a couple of applications (e.g. Lightroom). When I switch away from such an application to another one, causing f.lux to reactivate, it gradually changes screen temperature as it should.
However, if I try to dim my (laptop) screen to black - because I'm not using the computer for a while - it 'fights' me and keeps returning to the lowest level above black until it's done fading.

Of course this is not a very big issue but annoying nonetheless; and I think it should be quite easy to fix by watching the OS brightness levels and stop trying to actually adjust things when brightness is at 0.