Hi, I did the jailbreak with my iphone 4 mit iOS 4.3.2 und baseband 4.10.01. Now i would like to undo the jailbreak. I tried to install the non-custom 5.1.1 via itunes which leads to error 1601. Reinstalling itunes and changing the USB cable didn´t work. I then tried to edit the host-file leading to the same error message.