[...PMAGB-B...]
I installed the X11 sets from 7.2, and while the X server started up,
I didn't get very far past that. I ended up at a window that says
"Session Menu" at the top, with a text box containing the string
"chooseSessionListWidget", and "Default/Fail Safe" and "Cancel"
buttons available. Clicking the former ends up at a blank screen
(well, just the X background stipple and xconsole.
I'd say the X server issues are gone; sounds as though X server is
working fine. What isn't working is the (X) client setup. Depending
on how you started X, this may or may not be related to the version
mismatch between 7.2's X sets and the rest of your system.
Personally, I'd suggest using just the X server from 7.2's X, not
everything from 7.2's X sets. I don't know how easy this would be to
do, especially if both it and the rest of your sytem expect X to be in
the same place (eg, /usr/X11R7), but it probably can be done with
sufficient determination. (I expect the biggest headaches to be the
shared libraries involved, since some of them are used by both the
server and (most) clients, and I would not expect good results from
using programs from one X setup with the libraries from the other,
regardless of which is newer.)
"Session Menu" sounds as though it's coming from a session nmanager.
The rest of that looks vaguely as though some program is depending on
resources (in the X sense) for configuration, but is badly built enough
that its compiled-in defaults aren't sufficient for even minimally
correct operation. This makes me suspect you started X using one of
the "do everything" scripts, rather than manually.
Can you get a shell on it somehow when it's in that state, such as over
the network or on a serial port? I'd be curious to know what's
running.