Probably then what's happending isn't that Poser is locking up, but rather just having to work a long time to export the whole scene. Have you tried leaving it alone for a few hours to see that it eventaully exports the scene? If it is complex enough you might have to leave it overnight. Just out of curiousity, what are you going to do with this object file once you export it out of Poser? Perhaps an alternative would be to export small parts of the scene and then recombine them in the program you are going to use to import the objects.