Correct me if I am wrong. Is the reason I can't go from 5.1.1 jailbreak to 5.1.1 un-jalbreak because I received my 5.1.1 update from OTA (Itunes)
iClarified - iPhone - How to Re-Restore Your iPhone From iOS 5.x to iOS 5.x (Windows)
"Important***: You DO NOT QUALIFY for iOS5-to-iOS5 restores...