Dumb question, but in the Preferences do you have FBX set to export smoothing? It's, for reasons beyond the comprehension of mortal man, off by default.
If it helps, the problem occurs on the bottom section of the model if it helps even more the render that I have provided is default scanline render with no lights.
Now incorporated as the default in max, but still available for other versions - have you tried this? http://www.guruware.at/main/index.html Maybe it will help? :)
After baking my animation to the joints, deleting controllers causes the parts of the mesh affected by those controllers to default to their original unkeyed pose...