it gets to "do not disconnect" and then it seems the disc inside it goes mental but nothing happens and it doesn't react to anything. i've tried holding in the menu an play buttons etc but nothing seems to help. any suggestions? it's an oldish "classic" i think, 80gb. last time this happened i just left it until it ran out of battery, but i really don't want to do that now as it's fully charged and i was about to go out so would really quite like to have it with me.