I've had this problem ever since I've owned the machine and usually it's a minor inconvenience, though today it somehow launched the ball into the glass eep! Basically sometimes the ball will eject from the trough, bounce off the side and back into the trough. I'm trying to find ways to avoid that. A weaker coil I would expect might do the trick? I do have some mylar where the ball hits the side which might be making things worse (but wanted to minimize the already notable dent in the side) and I was thinking instead of placing some thin neoprene there, but wanted to get thoughts before I modded my machine any further.