could you post a screenshot of your render settings?  and also show how this looks rendered in Firefly, with another screenshot of settings?  the P4 render engine was very old, and i think it hasn't been quite what's actually  used in "Poser 4" renders since Poser 6.  i say that based on what could be a faulty memory of some posts, not so much my own experience, but i'm pretty sure others have witnessed discrepancies that show it doesn't actually duplicate P4/PPP rendering exactly.