bounds problems

I have two boxes stacked on top of eachother , set at the correct size, with rigid body turned on. when i turn on bounds= box, the bottom box collapses part way through the ground, and the top box collapses part way through the bottom box. how do fix this problem?

set the “size” setting ( pink doted circle) to the correct value, more or less
the box size

First you can browse those physics tips:

The first tip has a link to the latest physics demos, you can compare your setup.

And make sure you use latest Blender 2.42