I've got a factory unlocked, jailbroken iPhone 4S on 5.0.1. I'm on a Mac running Lion, and my iTunes version is 10.7. I tried to get to 5.1.1 by doing the following: 1. Tried doing a straight 'restore' of the 5.1.1 IPSW (9B206); iTunes didn't allow me to do this, failed with an error 21, and my iPhone got suck in DFU mode. 2. I read about the above error, etc, and folks were talking about how Apple no longer 'signs' 5.1.1, so I used Tiny umbrella v6.00.01 to do a restore by starting the server (my shsh blobs for 5.0.1, 5.1 and 5.0.1 had been previously saved). iTunes didn't like that either and wouldn't allow me to restore 5.1.1. (update: I noticed later that in Advanced settings, I had the 'Request SHSH from Cydia' enabled -- there was a warning indicating that this was no longer a suggested setting, but I am reluctant to retry). 3. Used RedSn0w to stich together the 5.1.1 IPSW and the 5.1.1 SHSH Blob, however again iTunes did not like that, and the restore failed. 4. in iTunes, I selected the 5.0.1 IPSW and somehow managed to get out of DFU and my iPhone restarted (sigh of relief). I'm back to where I started, which is a good thing, but I'd really like to know if this is possible to get to 5.1.1 (also Jailbroken), and what steps I should use? thank you.