As a last resort, you could try deleting the
HKEY_CURRENT_USER\Software\Microsoft\Windows\ShellNoRoam\BagMRU and
HKEY_CURRENT_USER\Software\Microsoft\Windows\ShellNoRoam\Bags folders within
the registry. Within each of these keys are other keys typically numbered 0,
1, 2, etc. it is within these number keys that folder specific information is
stored. Deleting the keys restores ALL folder information back to defaults.
It's a good idea to export the
HKEY_CURRENT_USER\Software\Microsoft\Windows\ShellNoRoam key to an export key
before doing so, just in case you want to revert back to your previous
settings.
Folder customisations aren't brilliant - especially if you're mounting
different drives.
Dan