A tipoff to that problem is if you start your sim (say at Misty's Place), go to slew and rotate directly slowly. At the same place during the rotation, the sim will "go to desktop". Unfortunately, if you sim is set to start your aircraft in that direction, it will crash on startup. What this means is you have a "bad object" ... and the fix you discovered will fix all of them. This "symptom" is totally repeatable, so if you have it, that's the problem.