One of the Aerosmith pins at Arcade Expo had the same issue. I don't have insight into exactly why or how to fix, but I did experience this too. The kicker would launch the ball towards the closed toy box, and it would bounce off of Jacky's head. Some people playing it thought that was intentional, but it seemed like a fault related to the toy box opening properly.

Right, I understand that the game doesn't always open the box (and I think its a cool little feature in the design) but when I was playing the game simply did not open the toy box. At all. (On a single-player game if that makes a difference). Every lock attempt would launch the ball into Jacky but the software clearly thought it was a regular lock (not a 'oops- you hit Jacky' type of shot).

This game was played a lot, so I wouldn't be surprised if that was a factor in the issue. In any case, I just mention it because it was pretty similar to what Phatchit ran into. Wish I had more insight into the solution.