I recently gave ARMA II another shot, after putting it on the shelf for a long time.
Am playing with the newest beta patch, 60393.
I was getting constant CTDs during saves (either auto or manual) in Dogs of War.
Finally, I noticed in the nvidia control panel, SLI and PYSX were enabled. So, I disabled both (in the global control panel), and wala, no more CTDs during saving. Also, got better framerates.
I was able to finish the game (and was dissapointed that Dogs of War is the last mission). How do you buy a damn heilo in that mission?! I completed it with a T72 and a BMP as my partner.
Anyway, turing off SLI and PHYSX in the nvidia control panel fixed the game for me. Its still far from perfect (I got several CTDs at other times) but I was able to win at least.