For what it's worth, there do seem to be problems with shaders made in C3 and rendered/opened in C4. I've seen a lot of info lost in the conversion, but ironicly it was simple stuff: like a single color in the glow channel kicked the whole shader to default.... (At least that's I finally decided was the problem.) Just suggesting that while you are rebuilding the models, you might as well look over the shaders too.