hello there, I have a JB iphone 4 with ios 5.1.1 on it. my modem fw is 04.10.01 its a GSM, AT&T phone..currently unlocked. it has been running very slow also I just started to have shrinking problem etc.. it works really fast on Safe Mode so I been thinking of removing the Jailbreak. the only reason I JB it because of MyWI tethering app. I am on the go most of times and I need to tether the internet to my ipad or macbook. Since now it can be tethered using Personal Hotspot, so I don't even need myWI anymore. however, it will be nice to have an IOS that can be Jailbroken if needed. I don't know how I can remove the JB properly. Do I need to preserve modem fw ? how can I remove JB ? or upgrade to a 5.xx or 6.1.2 thanks.