Drac, either I don't understand what you did or you messed something. I just exported an obj from Rhino. Two gloves of three meshes and three different materials each. In LithUnwrap, I redefined materials and combined each glove into one mesh. Cinema 4D plugin Riptide, when told to split by group, gives me two meshes with three selections/materials. Bryce 5.5 gives me a group of six meshes, each mesh a different material. When I re-exported the model from Cinema, unchecking Export Groups, I got six meshes in Bryce again. So three materials became three meshes again.

-- erlik