I've followed this tutorial to the letter:
So I've done the standard set up: Baked vertex colour into the mesh, created a MR Vertex Colour Shader, assigned that to a the colour of a Lambert and applied that to the mesh thats got the baked vertex data.
Then in the Connection Editor I connect the shape node (of the baked geo) 'Colour Per Vertex set' to the 'MR Vertex Colour Nodes CPV set'. That should work.
I can see in the viewport that the bake is working, if I turn the light off or press 5 or 6 the baked data is present. If I try rendering in Mental Ray with the lights off nothing works. The really annoying thing is that when I render with the light on I can clearly see the baked data.
Anyone had this before or can give me any hints on how to trouble shoot it?