[ubuntu-x] Ibex x server a little TOO hot-pluggy?

[Dan Kegel]

I just moved over to Ubuntu Ibex to get the updated
nvidia driver (which lets wine pass its video tests, yay).
Now the problem:
I'm running the wine tests on an automated test cluster,
and I had been perfectly happy using just one monitor
on all machines, moving the cable to the machine
I wanted to look at.

With Ibex, however, that seems to have broken.  Several
times I've moved the cable to discover that a
machine which had been running fine the night
before now is in reduced resolution mode, and
a nasty "reduced resolution, want to troubleshoot?" (not verbatim)
dialog is up instead of the test user's desktop.
I think this happens after just a few hours of no monitor.
This kind of prevents any useful work from getting done.

Is this by design?   Is the x.org server in ibex supposed
to throw a fit if the monitor is unplugged for hours?
If so, is there a way to inhibit this unwanted hot-plugginess,
and freeze x's configuration?

I suspect that to diagnose this I need to grab logs *before*
clicking "start a new X" on the error dialog.
But on the off chance there's something to be
gleaned from the post-restart logs, here they are:
http://kegel.com/wine/badx/

/var/log shows:
-rw-r--r-- 1 root root 32265 2008-11-03 05:19 Xorg.0.log
-rw-r--r-- 1 root root  9265 2008-11-02 21:28 Xorg.0.log.old
-rw-r--r-- 1 root root 36136 2008-11-03 05:11 Xorg.failsafe.log
-rw-r--r-- 1 root root 36136 2008-11-02 20:59 Xorg.failsafe.log.old

The test script shows that testing seems to have stopped
at 21:28 on 11-02, the same as Xorg.0.log.old's timestamp,
and shortly before the timestamp of the unexpected Xorg.failsafe.log.old.
Xorg.0.log above is after I came in and clicked "OK" on the
"should I restart X" (not verbatim) dialog.