Not sure if thats of any help or related to the crashes here, but who knows, so I'll give it a shot, too:
Playing on win7 64bit, 4GB ram
Never had any CtD/OOMemory-errors before 1.19 or 1.19a
When I'm playing in windowed mode, normal screen view, Turn 100/3 Cities built and am watching the memory usage of Elemental (via taskmanager, e.g.) it steadily goes up by approx. 1MB per ~8 Seconds - even if I'm doing nothing in game.
So I can just sit there Idly for ~half an hour, watch the memory usage go up/beyond 2.048kb and when I do something _then_ in the game then, it crashes. Kinda feels like it has nothing to do with the actual # of turn, just the kingdom size. (bigger kingdom = faster/higher raise in memory usage while doing nothing at all, thus faster crashing.)
If I'm looking at the cloth map in game, then the memory usage does not change at all (unless I'm doing sth ingame, of course) and thus I never got a crash yet when playing all the time in "Cloth map mode"
Good luck bug hunting !