I am working on a Flintstones that has a particular problem. When it launches balls, especially during multiballs, they will sometimes not launch all the way and end up back in the shooter lane where they sometimes fall back into the trough hole. If this happens while the ball save is on, no problem. However, it happens frequently afterwards, leading to multiballs that don't launch the right number if balls or just seem to end if you don't notice it happening. Anyone else seen this behavior and, more importantly, fixed it?

Can you show a picture or a diagram? I suspect I'm actually missing a piece.