I have downloaded the fpm and converted the game, and it appears to be working fine for me whenever I converted it?
I have uploaded the version that I have converted from the FPM you sent, you can let me know if it is working ok for you.
The only things I can suggest are, try recreating the level from scratch now that you have updated FPSC (i'm using 1.20 beta 18 just to see if you are using the same?). I'm not sure how FPM files are constructed, but it may be saving some old data that is causing problems. I do know that it has been reported before that levels do not convert well when created with old FPSC versions, so unless something hasn't updated right?
Or perhaps try re-installing the model packs, in case some things have become corrupt? I don't understand why it is doing this? As it is working fine on my machine?