check your normals, rigid body simulations are calculated based on normal direction, you're normals will need to be pointing out of the surface in the direction you want the collision to take place.

I.E. if you have a sphere that will bounce off of a plane, it will only bounce off of it on the side of the face that the normal is pointing out of. else, it will pass through it.
that would be my first guess

the other possibility is that the collision layers are different.
your active bodies might be on layer 1, and your passive bodies on layer 2, this would cause them not to collide at all, though they woudl pass through the table completely not in the way you describe.

another thing, did you delete all history before you set the dynamics up? maya hates history on dynamic simulations.

G-man