[ODE] Stacking objects

[Robert Rose]

Hi folks, I'm trying to do something that I thought would be extremely 
simple: stack three objects on top of each other.  Each object is just 
a rectangular block, and all begin "pre-stacked" in what is supposed to 
be a rest state.  I'm having tremendous difficulties getting the 
contact joint properties right so the scene behaves correctly.

When I run the simulation the blocks will sit quietly, then start 
shaking, and eventually one will blow up and fly out of the scene.  
Usually the one on the bottom starts shaking first.

Can someone please provide some insight as to how to set up contact 
joints so I can stack three blocks on top of each other and have them 
remain still?  thanks!

-robert