cckens, I'm afraid the filesize is about 19 megs. Which in fact might be one reason for the errors. As I exported just the one object that had the flaws, the flaws disappeared. I also started to think that the face of the clock is a part of a larger vertex object that has about 10 shading domains. It might be easier for the program if the shading domains were separate objects. I'm beginning to feel that this is something that has occurred when the computer has crashed while I've been working with the C-file. Computers tend to do it when I'm around.