A bit more information and something a bit strange.
My crash occured at turn 363 (1944)in a Large/Pangea/Emperor/Standard (high graphics, 2560x1440) game while there are still 5 other civilizations in existence.
I have consistently been able to recreate the crash when I try to use either an atomic bomb or a nuclear missile. The results are slightly different. With an atomic bomb, there is no display of the explosion before the system freezes - With the nuclear missile, I get the graphical explosion and radiation effects before the freeze. In both cases the screen freezes and the music continues for a minute or so.
Now the strange part. I continued the game without using atomic bombs or nuclear weapons until there was just one civilization other than myself. For a lark, at turn 389 (1969) I tried using an atomic bomb and everything worked properly. Just to be sure, I then used a nuclear missile, and it also worked fine.
Both of the tests above were performed within a few minutes of each other to make sure that they were both done with the same patch level and same system configuration.
Patch level 1.0.1.221, no mods
iMac 27", i7 quad, 16GB, Radeon ATI 5750, Bootcamp Windows 7 x64