I still get crashes (I'm in the midst of another OM career). I save often. Before and after every attack at least, and occasionally other times, if we've gone a while without a contact. Have you applied the Large Address Aware fix? I don't know what effect it might have on OM, but I found it essential to play mods like Trigger Maru and Real Fleet Boat. I had already applied it before I tried OM, so can't speak to it's effect. But as mentioned I still get crashes in OM even with it.
Read about the fix here
http://www.subsowespac.org/the-patro...ry-boost.shtml