gdm gives Xlib: connection to ":0.0" refused by server

[Robert Epprecht <epprecht@solnet.ch>]

Hello

I want to setup a box for my family, so there *have* to be things like
graphical login, kde or gnome and the like...  ;-)

But I have no luck with this box: Installation was a nightmare and might
very well be broken. (It's sid, as I could not manage to install sarge or
woody on this machine). I finally have X running, but graphical login
does not work yet.

If I try to log in as user 'debian' gdm (and also kdm) gives me
Xlib: connection to ":0.0" refused by server
Xlib: Protocol not supported by server

When I stop gdm/kdm I can log in as user 'debian' on a console and do
startx just fine.

Google gives a lot of information on the error message, but I still don't
get it :-(

How can I fix that problem?
Robert