It's been a few years since I looked into it, but I think because the Genesis items are not required to be grouped like poser content, the export doesn't know what to do with the object once it's loaded in Poser, thus you can't see it. It may be possible to use Dimension3D's dsf (not sure of the name) utility to load the hair into Poser with DSON installed then parent the hair to V4, but I never tested it. Otherwise, you can see if the Genesis 3 to poser utility has instructions for converting content and use that.