I have described my problem in greater detail on my favourite forum here but I think this could be a tricky one so I'm kind of cross-posting here in case the 1 person in the world who knows the answer doesn't see my other post.
I have feature classes registered with a class extension and I handle the OnCreate event whenever a feature is created. However, using the Advanced Editing / Copy Features tool the event is not fired and I can't figure out why. Any suggestions?