It's the flipper coils, they're just too powerful for the game. DE Simpsons is a great pin but be prepared for many, many airballs, especially off of the three-bank. This is why you so see many Simpsons with broken plastics, and also the ball seems to hit the side of the yellow habitrail a lot, so the yellow powdercoat is often peeling.
You get a sense after a while of how to make shots to minimize the frequency of airball shots, but they never entirely end.