Inspection lot created at GR on PO

Hi QM Experts,

My customer uses Inspection Lot for production.

We use a copy of 04 Inspection Type.  Inspection lots are created at production order release.

When activating QM I encoutered the following issue :

     - Some Inspection Lots are created for Production Order released before QM activation. Basicaly these PO, shouldn't be managed in QM since released before QM Activation.

     - These inspections lot are created following Production Order confirmation...

How can I manage QM activation without having inspection lots created for former production orders ???

Thanks a lot !!