Comment 1 for bug 751163

I sometimes see the same thing. Today it happened while playing a long running game of freeciv and the errors in .xsession-errors prior to the one where gnome-settings daemon crashed looked like:

(freeciv-gtk2:22823): Gdk-WARNING **: XID collision, trouble ahead

When gnome-settings-daemon crashes, it is very disconcerting as the entire desktop resets to some global system default theme and repaints itself. The sudden change is very jarring, and without any explanation until you examine .xsession-errors.