The two meshes you're comparing have the same shape, correct?  Yes, the only difference is the target has had all eyelashes vertices deleted. Otherwise, they are exactly the same.

And the error you get is simply that the script seems to stop responding?  Yes, no more error messages after fixing the referencing in the  .pp2 file.

How long have you let it run, in any given case, before bailing out?  A good hour I'd estimate, just gotten up and did something else.

And it may not make much difference, but what version of Poser are you using for this? Version 6.0.0.38

Are you lining up the heads in the 3D view before running the script?  Yes, they are precisely in the same position.

Step-by-step, what is the process you are applying?  **I popped the run_tdmt.py along this path C:Program FilesCurious LabsPoser 6RuntimePythonposerScriptsGeomMods and access it thru the python scripts window. The dialog box pops up, I select the source/target prop and then actor in the next fields over. Then I screen the mats, including only lips/skinhead/lacrimals, raise the octree to 12, then hit analyze meshes. I don't think I'm doing anything wrong here because I have gotten the script to work with other meshes.
**Perhaps I should turn the progress print statements back on while comparisons are being run, so one can tell that the script hasn't frozen....
That would be great.