**It's not really very complicated stuff, so it's kind of surprising and frustrating that this is often not handled well.**

Yes, thats true. I own Cheetah3d (MAC only, since I run MoI in Parralels) and was asking the developer over at the forums, what's happening. He told me, that vertex normals are recalculated automatically on import. So there's no chance I use this as a renderer without having to "polyflipweld" my ass off. :-)

Regards,
Sebastian