Physics behaviors halt after any PSD external updates.

Greetings!

Just updated CH to the CC18 to try out the new physics behaviors.  The SAMPLE physics puppet is cool, but as soon as I change ANYTHING in the PDS, the physics cease.  I've restarted, refreshed, re-imported the fresh physics puppet; same problem every time.

To recreate this problem:

Download the Physics puppet.

Import into CH.

Open the CH Media > Gathered Media > PhysicsPlayground.psd

Make any change (hide & show a layer.)

Save it.

Return to CH.  It automatically updates the file.

Physics stop working... no gravity.  No movement.   I can drag some items which collide with SOME items, but not all.  Green puppet loses limbs, which eventually return to him.

Anyone have any suggestions?

Thank you!