Doing some experiments, it doesn't seem to be leaking ram noticeably and I've not seen any save corruption (though if it locks up that does stop it auto-saving after the lockup, everything is frozen except the mouse pointer.
This problem does NOT appear to happen on Windows. I loaded the same save ...

Randomly during play the game will just lock up totally. The mouse moves, but the keyboard is totally unresponsive. I have to reboot my machine to recover.
This started in 1.1.19, 1.0 was solid as a rock.
I've not had the lockup occur before about 10 mins after starting, it nearly always will lock ...