[FreeNX-kNX] Blank Screen Failure - X & K Running Fine

[Info at quantum-sci.net]

Getting the classic logo then Blank Screen on client all of a sudden.  Debian server, Kubuntu client, latest packages.  

Tried a complete deinstall/purge/reinstall, several times on both ends, same thing.  I connect, it authenticates, I get the logo then blank screen...  but on the server machine it pops up a window saying, "KDE seems to be already running on this display."  It seems as though it tries to start the KDE session on the -server's- X instead of the client's.

There is no documentation on how freenx decides where a display should go, although in 2007 there was this problem which was fixed by changing an entry in nxnode from unix: to localhost: .  No one specified which nxnode file...  and that problem hasn't been reported since.  I tried the --display localhost:0.0 with the client, but it says " cannot connect to X server localhost:0.0".  Why, I'm connecting as the current user...

Shadowing still works fine remotely, so I know the core system are fine.  I tried doing nxssh --help, but it was upset that libxcomp3 (NX X compression library) wasn't installed.  Ah ha I thought, but installing that on client and server machines didn't help.

There is no documentation on exactly how this system works;  interaction between server, node, and client, so I am completely out of ideas now.

Can anyone please advise?