I am using 5.0 not jailbroken. I preserved my 4.10.01 baseband and my Gevey Ultra works. Every time I boot, though, I have to use the long process ( beginner 10 step process on
www.applenberry.com )
My wife's 4 is on 4.3.2 and uses the furiousmod jailbreak to activate the Gevey Ultra.