Here's another question- when the VUK sends the ball to the upper playfield, on my TSPP sometimes the ball bounces off the post a few inches below the scoop, and then falls back down the scoop hole (and sometimes repeats this several times before successfully making its way to the upper left flipper). Anyone else have this issue, or ideas how to fix it?
I've tried:
a) Lifting the little metal wire back up in front of the scoop that had gotten beaten down to the playfield level over time (which I assume is there to prevent the ball from falling back in the scoop). This worked for a bit to prevent the ball from falling back down the scoop, but it keeps lowering after repeated hits. How high is this metal supposed to stick out, and what keeps it in place?
b) Crafting a sort of cushion for the post to absorb the force and prevent bounce backs. Cushion inevitably ends up falling off after multiple hits.
c) Bending the metal guides on the left side at the top of the upper playfield.

Thanks for any thoughts!

This happens to me occasionally, when the ball is travelling especially fast. I've found that the monorail has some give to it- if you slide it a half inch either towards the top or bottom (see which works for you, i forget), it slows the ball down enough to not skip off the ramp at the bottom. Good luck!

You might need the couch weld fix:

http://www.pinballlife.com/index.php?p=product&id=1893

I had this same problem when I first got my TSPP, even running the latest code. When the ball gets stuck behind the drops, the code is supposed to signal the drops to fall and kick the stuck ball out. My drops would not always fall, and the ball would just be kicked into the back of the drops endlessly.

To fix the problem, I tried the following:
1) I ran the diagnostic tests to make sure the coils for the drop worked. They would fire, but sometimes not be strong enough to consistently cause a drop to fall.
2) I took the drop mechanism apart, inspected and cleaned it, looking for anything that might be catching.
3) I got new springs for the drops. The increased tension seemed to help pull the drops down at the correct time. This seemed to be the biggest help to solve the problem, though I still have the issue occasionally.

I have the same thing on mine.