Baking cast shadows?

I haven't been able to find a proper tutorial or google result explaining how to set up the lighting or material for this to happen. Essentially, Im looking to bake a texture from an object/mesh with a shadow cast on it by another object/mesh.

What are the requirements for this to happen? Every which way I try (different material and light settings) always yeilds the bake not registering an object is in front of it's light source, as if its invisible.

I'm using Maya 09 and Turtle for my rendering. 

object is in front of it's light source, as if its invisible.

And the object is marked as cast shadows and participating in reflection/ refracrion. This is the most commin mistake especially since importted objects have those flags off.

What are the requirements for this to happen?

Same as for normal rendering, you need to have a shader that accepts shadows