It's probably dead because Ipods suck. shoulda got a creative zen. You have nooooo clue how many Ipods do this and there is absolutely nothing wrong with the USB ports or cables, apple fails at something they started, thats kinda sad if you think about it lol. I seriously hear about these kinda problems every day.
Best MP3 player brands: creative zen, MS Zune, archos.
For smaller capacity players: all of the above plus samsung and sandisk.