Hi, have you tried to reset your iPod? Turn your iPod onto hold then turn it off again, do this 2-3 times, then hold your menu + center button, and hold for a few seconds, then the apple sign should appear. Then it should work. =]
I just downloaded some songs yesterday and today my ipod shuts down when I pick certain songs. The battery is fine. As soon as i pick the song, the screen goes blank, then the apple icon pops up and it starts running again. Can anyone help me out?