Hi again,
Here's the answer:
Microsoft.Office.Interop.InfoPath.SemiTrustà Wrapper Class (necessary for business logic)
Microsoft.Office.Interop.InfoPath.--> PIA (necessary for external automation)
The wrapper classes are built on top of the PIAs and are necessary to ensure that business logic assembles get the appropriate permissions.
Patrick Halstead [InfoPath MVP]
InfoPathDev
Patrick Halstead
Project Manager at Qdabra