Okay so the other day i restored my ipod, i tryed to add some music, about halfway through a song two errors popped up that said "could not copy to the disk "ipod" an error occured when writing to the device" and "attempting to copy "song name" to this ipod failed unknown error -20 occured. So i restored and updated to ios4 on a friends computer cause i cant restore on my computer, and the problem didnt go away. Please help me.