I have a jailbroken Verizon IPhone 4 with firmware version 4.2.6 on it. I'd like to upgrade to 5.1.1, but NOT upgrade to 6.0. I have installed TinyUmbrella and have the 5.1.1 shsh file saved to my computer's hard drive. I also have downloaded from some website a file called iPhone3,3_5.1_9B176_Restore.ipsw, which is supposed to be the 5.1.1 firmware. When I'm in ITunes and do a "shift-update" or "shift-restore," and choose the .ipsw file, I end up getting an ITunes error message towards the end of the process each time. I thought about doing a factory-restore, but I'm wary of ITunes updating my firmware automatically to 6.0, which I don't want to happen since, as far as I can see, there is no untethered jailbreak yet for 6.0. From what I've read on the Net, ITunes will automatically update my firmware to 6.0 if I do a restore.
Can folks please give me a step by step description of how I can complete this upgrade to 5.1.1? I think I might have to unjailbreak my phone first (maybe that's what's causing the error message) but I'm not sure. If I do have to unjailbreak, the only way I found to do that is to do a factory restore, which, again, I'd rather not do because of the risk of 6.0 being installed automatically.
Thanks for the help on this!