I used to call it "node drift", back in Poser 5 days, RedPhantom.  Err... assuming it is still the same phenomenon.  Nodes attached to the root would gradually move up and to the right, with repeated saves of the file.  I think eventually that manifestation was reined in, but I've been seeing a rightward drift with complex materials in Poser Pro 2014, largely when I have scrolled to the right to make some modification.  I've always used an inverted selection to drag the affected nodes back into place.  Or a script.

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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.