For now as a work-around, create a different folder separate from the My Documents folder to save your documents.
Do you remember when you started to have this problem? Had you installed any files or programs about this time?
Idea - Use system restore: Choose a date and time just before you started having the problems and restore the computer to that time and see if that fixes the problem. If you have installed any software or done any updates or upgrades between then and now, you will need to do them over again. If it doesn't fix the problem, undo the system restore and you won't have to worry about all the reinstallation stuff.
If this doesn't work, I've still a couple other ideas, and I'm sure the other members have even more.
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