As for the error logging, nothing stands out, the second theory was actually more related to the crashes that happen when you're repeating actions, or doing things quickly. Othello is a good one to crash if you try quickly flipping between the screens, if you take your time it's fine.
When you say "crash", you mean it locks up in MESS, but doesn't otherwise cause MESS to die, correct? Just so I know what to look for.
Lemmings and one other (I can't remember which, it only happened once and wasn't reproducable) actually crash the emulator, right back to the command line.
The others are just ingame lockups and usually occur when transitioning between scenes, or if something needs loading, even if that transition has worked previously.
and screenshots for today come from Dimo's Quest. This one works really well, although the controls seem a bit too sensitive (could be just like that tho, even on the lowest digital speed it seems to move 2 tiles if you hold the button down for more than a tap) It's actually a good game if you can get over that tho, I guess every platform needs to have 1 good developer, it's by the same guys as The Apprentice.