Cannot get X to start on some clients

[Brad Thomas]

I have setup a lab for the school here running an Edubuntu server.  My 
clients are having problems though.  I cannot get them to load X at 
times.  This is what happens:
1. I will boot one of my clients and it'll load up fine.
2. I then boot a second client.  I get the following after boot in a 
terminal window (no GUI login screen):
----------------------------
Ubuntu 6.06 LTS ltsp tty1
ltsp login:
----------------------------
If I log off of the first client, and shut it down, then I can reboot 
the second client, and it'll load fine.  However, if I try to reboot the 
first client, I get the same terminal login.  It's like only 1 client is 
being allowed to log in at a time.  How can I correct this?

Brad