The merge modules all seem to use self registration (even MS supplied ones despite MS saying this is no longer good practice

However the DLL's in the main project are "registered" using ISX's COM extraction - when the installer is run manually this seems fine - however when it is run using Microsoft SMS to do the install the DLL's from the merge modules have registered OK but the ones using COM Extraction have not registered - If I register them with RegSVR32 it is fine so it just seems the registration is failing - any ideas?