XFCE on Debian: Display lockups

[Jonathan Hepburn]

Hello everyone,

Has anybody else experienced this:

Recently, and I can't remember a specific event, but I can remember
that XFCE in Debian testing has had a minor running-tweaks upgrade
lately, I have been getting display lock-ups:

First, programs will stop responding to the mouse, but will respond to
the keyboard.
Then, programs will stop responding to the keyboard.
Then, nothing will happen, including CTRL+ALT+BACKSPACE X11
kill-with-extreme-prejudice, or switching to a different virtual
terminal.

At which point, I'm stuck with a complete forced reboot. And no, I
unfortunately can't try and log in from another computer to try and
see what's happening.

There's no CPU race, no unusual memory usage, nothing that my
admittedly novice de-bugging skills can notice.

I'm running NVIDIA drivers, which have done this sort of thing before,
but not for a while, and they haven't been updated recently.

I have had to switch back to WindowMaker, which has not locked up on me so far.

Any ideas before I submit a bug report with no real evidence attached to it?

Slainte,
Jonathan