There are a number of things working against you here in my opinion. First and formost, inside dops you have a few settings that are going to make bullet a bit less stable.
1)On the Rigidbodysolver I normally work with a MUCH lower penetration threshhold (something around -.001 is what I normally work with) that way objects have less interpenetration, and therefor react a bit more accurate with less spinning and jittering.
2)Also on the solver the substeps and constraint iterations I normally have set to 10, the default. While the change in accuracy isn't too noticeable with these, it also doesnt really change the solve time much at all so I wouldn't ever decrease them.
3)On your Rigid Body Glue Object, go to the Collisions Tab and under Bullet Data find the Collision Padding setting. It defaults to either .01 or .02, I make it 0, Always. When objects sit on top of each other this stops them from trying to slide and rotate off each other. Things will ocassionally pop a bit on the ground, but normally the autofreeze takes care of that first.
Those are just a few personal preferences for making bullet react in a more behavable manner. Note that all these values will drastically change how your glue is working, so its not just a plug and play situation youre still going to have to find the sweet spot.
The big issue, as already said, is the geometry being created from your Voronoi's clustering, its turning the top and bottom into difficult to handle geometry. This becomes an issue when you decrease the penetration threshold as it will cause your center to pop away from the base. You can probably fix this through using the newer GlueCluster tool, as it won't combine your top and bottoms into one piece like the voronoi tool does, it will just assign them a higher glue value then the center.
The help docs have a really solid example on the GlueCluster and how to properly set it up, but if I have time tomorrow I'll try and get it working in your file for you.
Edited by SteveRed, 20 July 2012 - 06:43 PM.