When trying to export STL files sometimes all that is left of the part is a shell of a few faces or just the hollow portions. When the file is exported a second time, almost always it turns out fine.  I was able to reproduce the error after a few tries of different geometries. 

Here is an image of the first to the left, and the second export on the right:

The second time I sent the file, there was absolutely no change to the file.  I did not even save the file or restart solidworks or anything like that. I exported this file using a macro from solidworks that sends the file to a network folder. 

Any ideas of what is going on and what can be done to solve this annoying problem?

I appreciate your help!

-Greg