Hi, this week end my Ipod developed black lines on the screen as well, I think it something akin to pixel problems, I have had something similar on a computer screen but they were white. I don't know any cure. Sorry couldn't help you, I am anxious about it has I have quite a few itunes downloads on it.
Hiya, I used to have a nano that developed black lines... I took it to Apple and they changed it for me right away as it is a fault with iPods that they don't usually see, probably a pixel problem but they were happy to give me a brand new iPod right away/ I hope this helps :)