iPhone OS 3.0: Error 13019 during sync: "If the steps above do not resolve the issue, attempt to sync an empty iTunes music library to the device while logged in as a new admin user. Follow these steps to create a new admin user:
Windows Vista and Windows XP
From the Start menu, choose Control Panel.
Open User Accounts.
Select Create a new account and follow the instructions to complete the account setup process.
Once the new account is created, choose Log Off from the Start menu.
Log in to the newly created user account.
Mac OS X
From the Apple menu, choose System Preferences.
Choose View > Accounts.
Click the ' ' (you may need to authenticate to be able to click this).
Give the new user a name and short name and enter a password.
Select the checkbox for 'Allow user to administer this computer'. This makes the user an admin user.
Click Create Account.
Log out and then log in to the new account."