I've already spent the past 4 hours trying to upgrade my ipad 2 (wifi only) to 6.1.2 but the !@#$%^& error messages are killing me! My ipad2 is at 4.3.3 now, jailbroken. I downloaded the ipsw file for 6.1.2, fired up itunes, shift+update, choose the file. No pain there... until it pops out a message error 3194. Go online, yada yada yada, downloaded tinyumbralla, started ipad2 in dfu mode, itunes detected ipad2 in recovery, choose file.. then it gives me error 1600. Search online for error 1600, saw I might have a faulty cable/usb port. Changed everything, still the same. Downloaded ireb, ifaith, but apparently those only work with iphones. Could someone kindly guide me on upgrading my 4.3.3 to 6.1.2?