I'm on 4.3.3 but when trying to update to 5.1 through Apple's update service in iTunes I'm getting a variety of issues, the most common being 1600, 1601, and 3194. My device was jailbroken and is now stuck in "DFU/Recovery" mode. Please help, I've tried this on other computers with the same errors, I've ran out of ideas. Edit: I fixed my host files and only get 1600 and 1601... I've tired iReb and restoring after that but I get the same error.