I used this guide http://www.drivard.com/2012/06/installation-freenx-server-ubuntu-12-04-lts-precise/ to install freenx and it is working fine apart from 1 thing.
I can't seem to be able to disconnect from sessions. If I try to close (from the 'X' button top right) a NXsession from the client pc nothing will happen. In other setups where I use NX to forward desktops sessions, I would get a gtk , or ncurses windows asking me if I want to terminate (=log out), or disconnect from the session.
In this case nothing happens when I press 'X', and I can only choose to log out from the session (as I would locally).