Comment 2 for bug 751163

I have been experiencing this same problem for several months now. It always starts out as a sudden, dramatic increase in the amount of time that it takes to simulate the AI players moves after I click the "Turn Done" button (CPU is always pegged at 100% when this happens). After that point, scrolling around the map or anything else that requires redrawing a significant portion of the screen lags terribly and will peg the CPU at 100% for brief periods of time. Fairly soon after this happens, I see the same behavior that Phillip reported with the desktop suddenly reverting to a default theme and set of icons. Running the following script usually brings all of the icons and widgets back to the normal theme:
  killall gnome-settings-daemon
  gnome-settings-daemon &
  killall nautilus
This is usually only temporary, and after 10-15 minutes I'll get dumped back to the default theme again. Completely restarting the X server will usually prevent the problem from resurfacing for an hour or so, but it only delays the inevitable.

I have also had this problem occur while running nothing but Firefox, but the vast majority of the time I see this problem is when I'm running Freeciv.

I modified my script to save a copy of .xsession-errors when it tries to restart gnome-settings-daemon. I'll attach it to this ticket in case it contains anything useful. Is there anything else I can provide to help debug this issue?