No, my materials aren't double sided, the normals are fine on the original model, they flip on export. I wish I could find a common trend of whats causing it, but no dice. I've done completely custom meshes that have come out fine, I've been working in 3ds and Maya for a long time, my geometry does not have any problems with it. I am almost sure it is a bug with the exporter, since this particular instance happened when I did modifications to a helmet that worked fine before, then upon export, the helmet's normals were flipped (the entire object, not just an element like I had said earler). I had to end up importing a working version (which I could also have done by pre-flipping, exporting, and then importing). There is some aspect to my geometry, some sort of hidden property, that is causing the exporter to malfunction. With we had Verctingorix to figure it out.