If it were game logic, though, I don't imagine it would be limited to such a small set of players (possibly only on Macs, though I'm not sure of that), and it probably would have showed up before the engine switch (since not much game logic changed after that point).
It may not be graphics per-se, but related to the engine more than the game logic.
That said, a save where it reproduces at least on the original machine would be great.