So, I've tried it with LaFemme. Works in Poser 12, works in Python 2.7 on the command line. But I'm getting different numbers for the mesh:

    Loaded mesh with 386835 vertices and 383504 faces.

Whereas you had:

   Loaded mesh with  387296 vertices and 383752 faces.

So I'm still not sure if that's a P11 versus P12 thing, or LaFemme versus LaFemme Pro. It might be interesting to try a different figure. And it's probably useful if I add some more diagnostics and make the script bail out right away if the face counts don't match.

-- I'm not mad at you, just Westphalian.