My own experience is that Poser itself can do some weird things with recording texture references. That is, Paser 5, and maybe not the latest version, but change a texture in the Material Room and it is possible for the new file to record the data in an incorrect form. I'm semi-confident that SR4 has done something about this. Also, as a Poser 5 user I have been led to believe that Poser 4 is more restrictive on the organisation of folders.