Trying to get large file to a friend, using idisk utility. Utility can tell me how much space there is left on my disk so obviously recognises me, but I can't load disk or public folders!? It says 'user unknown... and yet, when I changed my settings so that people would require a password to get to my public folder, it knew this, asked for a password, then said again 'there is no such user'!? help!