Ok, here is the update: It really seems that the Community units mod was the culprit. I am half way to the Carribean now, 4 ships sunk and no crashes so far. On the other hand most of my crashes happened why attacking the convoy. These four were lone targets.
I will definitely keep posted.
The only thing which sucks is that I am loosing the "variety" of the targets. Well, I guess I will have to trade quantity for the quality.
