I have only the one folder, from a Curious Labs Poser 4.03 CD, are you sure the duplicate folder is from Poser and not your copied Runtime? Anyway, Poser 4 is extremely dumb - the Runtime folder must be in the folder with Poser4.exe, and the Geometries folder must be in the Runtime folder, and the object files must be in the right folders within that. Have you tried using Poser's File>Import>Wavefront OBJ to bring in one of your object files, just to make sure they aren't corrupt?