I am currently on 3.1.3 with firmware 05.12.01 jailbroken with Spirit. Would like to upgrade to ios4 but I am getting conflicting info as to the best way to do it or if it can even happen. I'm a bit of a newbie so the more I read, I start to get myself confused. Am I safe to just do the update, and use jailbreakme.com to re-jailbreak? If so, will I lose apps such as sbsettings and 3rd party apps that been installed?