In this tutorial we learn how to fix 1600 errors when jailbreaking 3.1 firmware. First, make sure your iTunes is updated to 9.0 and make sure you have 3.0 firmware. Having these installed on your phone will help make sure you don't get the 1600 error. You will have to play around with your device to see what works to remove the error. You can also hold the power and home button for several seconds to place it into DFU mode, which should help you install new programs onto your phone. When finished and the errors are removed, your phone should work perfectly!