according to the apple website here is some help with the solution.
this is taken straight from apple.
or updating an iPod in iTunes 7 or later, you may see a dialog
reporting "An unknown error has occurred" followed by the error number
1415, 1417, 1418, 1428, 1429, 1430, 1436 or 1439.
iPod, iPod mini, iPod shuffle, iPod nano, iTunes 7 for Windows, iTunes 7 for Mac, iTunes 8 for Mac, iTunes 8 for Windows
If you are experiencing these errors, begin by updating to the latest version
of iTunes. When you have the current version of iTunes, try the following:
- Disconnect and reconnect your iPod and then attempt to restore.
- Restart your computer and then attempt to restore your iPod.
- Disable or Enable Disk Use on your iPod and then attempt to restore.
- Try connecting your iPod to a different USB port and then attempt to restore.
- Remove any third-party USB devices you have connected to your computer (it is not necessary to remove your keyboard or mouse).
- If you use Windows, re-register .dll files as described in article iTunes displays -50 error message when syncing iPod on Windows XP
- For Windows users, update or reinstall your Windows USB drivers.