Comment 14 for bug 400830

Another thought:
Could this problem be solved with extended attributes? Nautilus-share could add an extended attribute to each shared folder, which would contain a unique identifier, which would map into its list of known shared folders? This, it seems, would be a more reliable solution than tracking files by path and would prevent the kind of confusion demonstrated in this bug and others like it.

Of course, extended attributes aren't enabled by default in Ubuntu, but that's easy to fix.