If it is the Poser.rsr, as I think Geogress is suggesting, you can supposedly offset this sort of problem by making the Poser.rsr write-protected. Do the PZ3's that continue to be a problem have anything in common? If they all use the same files and the PZ3's that are okay use different props and characters, that might indicate that the Geometries .rsr's are corrupt. Dang, I hate a re-installation. Sorry to hear about that. :(

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Cage can be an opinionated jerk who posts without thinking.  He apologizes for this.  He's honestly not trying to be a turkeyhead.

Cage had some freebies, compatible with Poser 11 and below.  His Python scripts were saved at archive.org, along with the rest of the Morphography site, where they were hosted.