Well, I did not copy from a CD. it's just a file I made 8 months ago that goes into every project folder I have (I have about 200). It was not a problem until a week ago. And I find it odd that if I close it and then open it again it saves fine.

I will say that I changed the sharing on my pc to allow another pc access to the main work folder that all of these files are in. Would that be an issue?