Non LTSP clients cannot connect to ubuntu 8.04 LTSP server
some of our clients (vxl-itona) have necessarily a local Linux OS (Gio-Linux)
on flash ram. They are able to connect to an opensuse 10.3 server with kde
via xdmcp. On the server side xdm was used as display manager.
The new server is ubuntu 8.04 which is configured as LTSP-Server. Clients
booting the chroot image from this server are ok.
In order to allow xdmcp connections I configured the ubuntu server with the
graphical gdmsetup as described in the edubuntu handbook . I can ping the
client from the server. When I try to connect to the server the terminal
shows a black screen with cursor. If I switch to the terminal's control panel
it shows "connection active".
Are there any steps left out in  which are to be customized in order to get
a login screen?
One assumption why it doesn't work is that the terminals cannot connect to gdm
(as we formerly connected to xdm). Can I substitute gdm by xdm on the ubuntu
box without loosing the LTSP clients which connect via ldm?