Hi the other day my Nano froze at a screen with just the apple logo on it and will not do anything else, (not recognised when attached to PC - XP or Vista home) If I leave it long enough I will get a message to plug in for power but that is it. I have tried to set it to disk mode; I toggle the hold switch, hold the menu and select together for 6 seconds and it appears to shut itself off, the apple logo returns and when I hold select and play to put it into disk mode nothing happens. I have tried a variety of combinations of buttons but to no effect. Is there anything I can possibly do? Thanks for all advice