I tried to use iTunes, reset using the phone Reset in the phone general settings, hold home button to get restore activated.. it just says unable to restore due to unknown error. It was jailbroken before but updated to 5.1 with no problems... alhough the cydia icon is in the phone but it does not work at all. I am just trying to get it all clean, reset and sell it.... but unable to. What else can I do. I have jailbroken many phones and android ones [all my own phones... not for others] but this one is hard. Any advise?