I'm interst to this post too.
My issue is that I'm not able in Acrobat 9 Pro to change the 3d model shader.
I'd like to give it different appearence touch, modifying the shader (color, specular, glossiness, relfectivity.. and so on) and I'm noticing that Acrobat 9 Pro doesn't allow it.
So I think I should set it before importing.
Am I missing something?
Thank you very much for any explanation.