Thanks :) But I've seen people talking about rendering shadows separately and overlaying them on the image when done. So it must be possible. I just don't know what I'm doing that is wrong.

It seems strange that Poser would give the ability of being able to render just shadows and have it be totally useless by having them  appear on a white background. What is the point of rendering shadows by themselves if that is the case?

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi