Comment 12 for bug 231034

It is quite possibly an infelicity in the way Metacity and Emacs interact. There are not a few of these. GTK-Emacs is not your ordinary GTK application, since it has the Emacs event loop and GTK's event loop and possibly a few other things running at once.

I don't know whether it happens in other window managers, and if anyone feels like checking they should go ahead, but anyone who can reproduce the bug in Metacity should turn on logging as described at http://blogs.gnome.org/metacity/2008/03/07/logging/ , reproduce the bug, restart Metacity, and then attach the log here (or mail it to me or someone else who knows Metacity's guts) for analysis.