Hey brian... That happens to me some times too.... did you make all the blendshapes from the original head?

Sometimes it messes up if you dont make all your copies form the original... Do not freeze tranformation on the copies...

Try selecting all your targets in one selection, than shift the original then create blendshapes.

If that dont work... I just redo them, there my be a way to fix it but I havn't figured it out yet.