I'm plugging in my sister's ipod on my computer and the ipod shows up on the desktop, but not on itunes. I've plugged her ipod into my computer before with no problem and was able to add songs to her ipod. But now it won't work. Can anyone help? I guess this relates to adding a second ipod on your itunes. My ipod still shows up on itunes when i plug it in, but my sister's won't anymore. Please help, im frustrated