I just recently moved my iTunes library off on onto my 250 GB USB External HD to try and free some space up on my internal hard drive. The iPod and HD were plugged into the same USB2 hub. All was fine until iTunes tried to synchronize some new TV shows I had downloaded. There wasn't enough space unless it removed my photos, so I told it that was fine. Then the trouble started. iTunes almost stopped responding while completing that task. Then, it started having issues. Every five or so minutes, it comes up with an error, like, "Attempting to copy to the disk "Caleb's iPod" failed. The disc could not be read from or written to." I reset my iPod and it still happens. After each message, I just restart the sync and it continues from where it left off. Five or so minutes later, the message reappears. I changed my setup and moved the HD and the iPod so each is plugged into its own port and the message still came up. While I was typing this, it miraculously transferred 10 or so GB without error. Why is this? Is it because the USB2 bus doesn't have enough bandwidth to handle both the iPod and the HD? How can I fix it?