Are you using the 3.6.8 mediaVPs? If so, I can help you with this, as I had the same problem.
1) Open mv_models.vp with VPView.
2) Extract "newhornet.pof" to your models folder (either for Derelict/data/models or Freespace2/data/models).
3) Rename "newhornet.pof" to "New_Hornet.pof"
That's how I got mine to work.