No, I've never touched the game files except to extract that one special zip from completing the main game (That I did with no problems, no crashing or anything)
I did verify fame integrity cache already with no change.
A game crashing? Yes. Borderlands, Minecraft, Portal 2, Sims 3 all run without a problem (recent games I've also played.)
I did start up a normal game and found the same problem there as well. I have updated my graphics drivers since I originally played the game last (and completed it), but it seems to happen strangely, I could open my inventory fine, then when I closed it, played, and went to refill my oil, the game crashed.