On mine, the Cliffy causes this. When the ball approaches the scoop from the left flipper, it bounces slightly on the Cliffy, causing it to go airborne and hit the scoop's "scoop". When the ball approaches from the right side of the scoop, it has a tendancy to ride along the side of the Cliffy. Apparently this is a common issue. I've considered trying to take it off and seeing what damage it's covering. I wish there was a Mantis protector for Ripley's.

-E

I looked for shrunken heads on eBay just now and it makes me wonder if the Stern head wasn't just an off-the-shelf part. It's very "bizarre" how many heads look like they'd work.

Look at ebay.com link: Realistic Mini Shrunken Head Set Of 2 Gag Joke Novelty TIKI BAR DECOR
and
ebay.com link: Loftus Shrunken Head 4 5 Decoration Prop Black
just as a couple of examples.

Mine had the same problem. The cause is the screwhead has dug into the screw hole in the ball guide. I put one of those small star-looking lockwashers on mine to keep the screw head from sinking into the hole. It does make the head stick out slightly but doesn't affect play.