I think that you are setting a wrong ```KDE_PATH```.
In my system (Linux Mint 15 KDE) there's no ```/usr/lib/policykit-1-gnome/``` folder.
I have ```/usr/lib/policykit-1/polkit-agent-helper-1``` and ```/usr/lib/kde4/libexec/polkit-kde-authentication-agent-1```.