My son and I both have 4G ipod touches. We use the same apple id and just sync our ipods by playlist. The computer we have our itunes set up on is an HP desktop. It will recognize my ipod but for some reason will no longer recognize my sons. Out of curiosity I had him plug his into his macbook just to see if it recognized it and it does. both computers are running windows xp. any ideas as to why the desktop wont see the ipod?