Strange Crash when combat ends

[CurtisJasper]

I find that my game frequently crashes not when entering or during combat, but when combat ends. The circular progress bar gets stuck about 20% or so in, and looks like it "tries" to load the rest, but stutters and stops. I'm guessing this is related to loading the main map and environment, because it only appears to happen in regions with lots of detail or activity.

For reference, I am running with the lowest settings possible on a middle-end machine with 64-bit VISTA.

Does anyone have any ideas?