My boss bought himself a new iphone 4 from hong kong and he wanted me to unlock it so he can use any carrier .... I thought i could jailbreak it cause i jailbroke my ipad and itouch both on ios 4.2.1 using greenpoison which was pretty str8 forward .... But on the iphone4's screen there is a note saying please insert a valid sim card. The same message is displayed even in itunes and i cant do anything. Can sum1 help me out with this problem. I've already downloaded the 4.2.1 firmware and greenpoison for windows !! Thnx in advance !