This may be as designed or I have never noticed this before but a customer came to me today with this example and issue.
I have attached 2 parts to this post that I created to simulate the issue and I get the same result.
Is Inventor designed to exibit this behavour or is this a bug?
That's definetlly a bug. When you open part B and you click on Edit Deriverd Part all the sketches appear correctly. but as soon as you click OK they revert back. Maybe Inventor is just copying the sketch entity and the format comes from the current active sketch (not original).
I would file this as a bug or post an ideastation: http://forums.autodesk.com/t5/inventor-ideastation
I think part of the problem is in the changing of the profile by changing the lines to construction. Inventor isn't smart enough to deselect the original profile, it only will change the shape/size of the original profile.
Not really sure if you could call it a bug/issue. If you were working in a single part and changed the exterior lines to construction from solid what would happen, would you get an extrusion of the smaller interior shape or would it thow up an error.
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