Since we started having Vista computers arrive in school we began notice we could no longer see the username on the documents folders, instead getting lots of folders named NAS\My Documents\My Documents (see picture). This also happens with Windows 7 but we have now found the solution.
If you are redirecting your users documents and are having the same problem:
Go to 'folder options' (via start menu or control panel) and then the 'view' tab.
Untick the box that says 'hide protected operating system files (recommended)'.
Browse to where you keep your users documents.
Inside the first 'My Documents', the one that should say the username, look for a desktop.ini and delete it.
Do this for each affected folder and when you go back to your shares they should all have the users displayed. You could create a script to do this for you and if you assign it as a scheduled task you could have it run automatically at specified intervals.