Created attachment 268608 [details]
Debian-generated software version info

When I close the last window on a desktop, windows from the desktop above (or, more generally from other desktops) appear to flash up briefly before disappearing again.

I've recorded a brief video of the phenomenon:

http://tiker.net/tmp/flashing-windows.webm

Here's what's going on:

1) I start the video recording in a terminal window.
2) I switch down by one desktop
3) I rapidly close and open a few terminals (by keyboard shortcut)
4) As I do so, you can sometimes briefly see the window from the desktop above flash into the foreground

It's super-annoying, and sort of messes with the polished appearance of Gnome...

I'd much appreciate any help. I've attached a summary of my software versions, as generated by Debian.