This is a recurring problem, it tends to happen more frequently later on in games (200+ turns). If I wanted to try and reproduce it, the best chance I have is to: 1) Start the game 2) Load a saved game with 200+ turns 3) Press next turn a couple times 4) Try to save game.
This isn't nearly the only time it happens, but it would be the easiest way to recreate it quickly.
Another way I crash often is trying to load a saved game after playing a game that's 200+ into turns. This crash doesn't give me an Out of Memory error like the other crash, it just gives me a generic windows crash window (asking to look for a solution online etc..)
I'm) including my debug.err and my saved game
os: Win7 64bit
gpu: ATI 5870 (10.8 drivers)
mobo: 790FX-GD70
cpu: 955BE
ram: 4g 1600