[K12OSN] fl_teachertool can't broadcast on k12 6

[Peter Scheie]

fl_teachertool 0.41 on my K12LTSP 6 system can't broadcast to clients. 
Monitoring works, as does lock (invoke screensaver).  I've enabled 
X4_MODULE_02 = vnc in lts.conf and rebooted the clients. This happens 
whether I run it as root or as a user who's been given permission via 
sudoers.  When I call fl_tt from a command line and try to broadcast, I 
see errors like this:

/usr/sbin/teachertool-vncviewer: ConnetctToTcpAddr: connect: Connection 
refused
Unable to connect to VNC server

If I run nmap against a client, it shows there is a listener on port 
5900.  I copied the .vnc directory from root's home directory to 
/opt/ltsp/i386/root/.  I'm stumped as to why the connections are being 
refused.  Anyone have any ideas?

Petre