I worked through BlenderGuru’s great wrecking ball tutorial and decided to build on it to create my own Rube Goldberg Machined. All was going well until I duplicated one of the blocks (the selected piece in the attached image). Whenever I run the system this block bounces off the surface before and of the other blocks reach it. What am I doing wrong?

If I’ve done this correctly, the blend file should be attached below (I am using Blender 2.69).
rube_goldberg_machine.blend (1.43 MB)
The steps were set as a convex hull; change them to mesh and all is sweet