Hey guys question, my iPhone 3GS is 3.1.2 and won't let me down a game called Angry birds cause it says I need 4.0 or higher. Is is safe to hook up my Iphone to the itunes and upgrade up to that while my Phone is jailbroken? I haven't hooked up to iTunes in like 3 months since I Jailbroke my iPhone so I don't know if its safe or will erase everything.