As Dave says, don't scale the figure on import. Make (or scale) your OBJ mesh the size you want it to be before Poser-ising it. Once you've converted the PHI hierarchy, open your newly created figure and save it back into the library before you do anything to it. You may have problems with the JP editor otherwise. Other than that, the Anim8or -> UVMapper -> PHI -> slaving over JPs route should work; it does for me. It isn't easy, though. ;)