Windows Explorer Issue

[Qui-Gon John]

I was helping someone who had a problem with files disappearing while working in Windows Explorer. She would open and close various Word docs from Windows Explorer, copying and pasting different sentences or paragraphs among the documents. Every so often, one of the documents she had been opening would no longer appear in the list of documents in Windows Explorer. I saw this happen myself, as she showed me the problem.

If we "refresh" the list or close Windows Explorer then reopen to My Documents, the missing file is back.

Does anyone know what is causing this?

Are there any known solutions to prevent it from happening?