I jailbroke my iPhone a month or so ago using the application Absinthe. Everything has been fine with it. But I have found that I do not use all the features that much and would like to go back to the original iOS and update to 5.1. I first tried letting the update happen automatically but it always ended telling me that my iPhone is not eligible for the update which is clearly wrong. I then tried putting it in DFU mode and option clicking restore and installing 5.0.1 IPSW i downloaded off the internet. That gave me the 1600 error. I even tried erasing and restoring from factory settings on the iPhone but it would go black then the rotating loading icon would sit there and not go away until I held the home and sleep buttons to turn it back on. I am not sure what other options I have in this situation. My last resort is to smash it and go and pay $50 bucks to get a new one from the apple store with my applecare+. If anyone has seen this or can help I would be greatly appreciative. Thanks.