Have you tried asking on the Lockheed Martin P3D forum? They are usually very helpful. Also without knowing how your rig is set up it is not really possdible to give you any advice. All I can say is that P3D works fine for me on my machine and I never use FSX anymore.
Jason Kirk
I'm sure I replied to this topic yesterday. Just copy the complete folder in FSX and insert it in the the LM P3D folder. All very simple and worked for me. No need for any further faffing about.
Jason Kirk
Just copy the whole aircraft from you flight sim X simobjects folder and dump it straight into the same folder on your LM P3D. Simples. That is how I did it and it works fine.