Philywebrider must be on Windows if he's using P3DO. For, say, "Vicky Beach Tan MAT.pz2" there should be a file called "Vicky Beach Tan MAT.RSR" or one called "Vicky Beach Tan MAT.PNG". When you rename the PZ2 to "MAT Vicky Beach Tan.PZ2" you also need to rename the RSR/PNG the same way. That's the advantage of using P3DO - it does both files together.