Another tip that may help if you do use the layer shadernode and must get the exact texture as a bump or displacemant. I think you can just dup-it and then mape the same node to the bump value , but if it dosen't like that I think you can do a convert-to-solid-texture per object mapped for the layered shadernode and get a single file texture that you can then map to the bump value or take it to a paint program and make it greyscale add a little blur and bring it back it . I think you can convert a layershader to a single picture file this way , but havn't had the chance to try it . Anyway , hope it helps a little.
"..you know, its hard to get people to pay you to make dancing robots.."
--Mr.K
"..you know, its hard to get people to pay you to make dancing robots.."
--Mr.K