This is what I get in Superfly when I select an image and set the am occlusion. If I go in the material room and and click on Set up IBL, I can choose the same image and it will render. But what I didn't realize was happening is that Poser has switched me to firefly and that is why it is rendering. When I switch back to superfly and render again, this is what I get. The silhouette. 

IBL Light settings

The ground is hidden. Otherwise you would have a solid black image. But I verified that visible is unchecked on the ground.