> My guess is that the program that init is supposed to be
> running to start the display manager is failing.  On my
> RH 7.2 machine, the last line of /etc/inittab is as follows:
> 
>     x:5:respawn:/etc/X11/prefdm -nodaemon
> 
> Have you tried running this by hand to see what happens?

Yes I have. It just sits there looking stupid.

> If it fails, you might also try
> 
>     sh -x /etc/X11/prefdm -nodaemon
> 
> in order to display the commands being executed as the shell runs.

Tried that, too. The last thing it does is exec /usr/bin/gdm -nodaemon, which is exactly what I thought it would and
should do from looking at the script. But there is no login.
Anyhow, I don't know how it could start a graphical
login program while I'm already logged in, so I didn't
expect that to help.