I am really wanting to upgrade to the latest firmware for my iphone. I'm still running OS3, everything works and i haven't had any major issues. I'm just scared to update because i've been hearing about people having issues with Push and other things not working. Is it still an issue with the new baseband not allowing to unlock? Do I need a custom IPSW? or can I just restore/install latest via iTunes and run blackra1n to jB/Unlock? I'm sorry ( I know theres probably other posts about this) i'm just nervous about upgrading because i need my phone daily and i don't need a brick lol. I've been reading guides to unlock/jb on iClarafied and it seems pretty straight forward. so if its just that easy i will do it, but i don't want to brick my phone or be without push.. I have an old ATT sim card will this work while "activating" my phone?