Attempting to copy to the disk “DAN HILL_S” failed invalid file name

Hi experts,
I am trying to copy a song from my disk to iPod. I have the same errors with another songs and nothing seems to work. I stopped all the open processes thinking maybe I cannot copy while the song is playing. Can anyone help me to solve this error? What could cause this and is there a problem with my iPod?
Thanks!

Attempting to copy to the disk “DAN HILL_S” failed. The file name was invalid.
