Well, I am counting on when you say "My Documents" that you mean it and not Documents.
Anyway, the My Documents folder in Win 7 is just a link or "node" to your Documents folder. I was thinking possibly it had gotten in some type of loop and kept making new links, or the links somehow were pointing at each other.
So, first, right click on the My Documents folder or My Music folders and select properties. Then go to the Location tab. It should point back to the Documents folder or Music folder. If the path is different from below, that may be your problem.
C:\Users\YourUser\Documents
C:\Users\YourUser\Documents
You might check a couple of levels down to make sure it does not change. If it is different, post back.
If it is not that, possibly some flag is not being set to tell the system the link has already been made and to stop making more. I have no idea where such a flag might be, even if there is one, but I will try to find it.
Have you ever tried to move your My Documents folder in XP or Vista or Win 7?
And anytime a system is doing something it should not, one answer might be to do a repair install.