I've come across several problems over reflections being handled differently in Poser and in Studio. The basic Poser model is derived from the Phong shader system, Diffuse, Ambient, and Specular colours/textures, and Specular Highlight size. I'm guessing some, but what you describe could be a Specular Highlight problem.

This Phong model is a simplification of reality. A glossy material has small Specular Highlights. I've seen signs that suggest Poser and Studio store that information in very different ways, which get mistranslated.