Public geometry issue with Creo8

[Acido]

Hello,
We have been using public geometry in an assembly for several years (creo5) and within this public geometry there is a composed surface (bottle), which we use to hollow out another part (mould). The usefulness of public geometry is that we change the bottle to another and the mould automatically updates itself (height, diameter etc) to match the new bottle.
However, since we have been testing Creo 8, we have not been able to change our bottle without causing an error: it does not replace the old composed surface with the new one.
I am trying to attach a video to show you our problem.
Maybe we have done it wrong for a long time, but our files are like that. If we have done it wrong, what should we do?
Thank you in advance for your interest in my question.

Regards