I'm having the same sort of problem off and on. Sometimes you get no textures at all and Bryce 6 doesn't even ask where they are. Sometimes the textures are loaded but the model comes in black or gray anyway. I click on an individual mesh and check materials and the texture is there. If I leave things alone it's still gray or black. If I change any setting by a fraction suddenly the texture is applied and shows up.

I never used studio but exported poser obj files. When I did this in Bryce 4, 5, 5.5 I would open just the object in a blank scene. It was much easier to ungroup thte object and go through the materials withou other scene objects getting in the way. I used to group at the end then select and copy the figure. If I kept Bryce open I used to be able to open my main scene and paste the figure into it. Bryce 6 clears something so I can no longer paste. There is nothing there to paste anymore.