How do I install FreeNX server so that it works correctly?
Solution 1:
First of all, the nx user is a system user (id less than 1000) so he is not visible in System->Administration->"Users & Groups", you should see him in /etc/passwd.
Next, I use freenx server without custom ssh key, so I suggest to make it to work without the added complication of custom key. I restore my security using the firewall to deny access to non desired clients.