FunctionFlip doesn't work. Alternative/fix? I am on OS X 10.9.5 and recently (can't remember if this happened during 10.9.4 or not) 

FunctionFlip has started to work very inconsistently for me. 

Basically I use this to enable the F1-F10 keys for use in terminal (and some of them I set to do stuff like next/prev. tab e.g. in web browser) and I used FunctionFlip to generally enable the volume control keys so that they work globally. 

But lately it's just not been "kicking in" so it's hit and miss every time i try to change the volume.
I got tired of FunctionFlip not working right and finally found Karbiner does exactly what I want and works great.