I just purchased a new Iphone 4, ios came with 4.2.1 firmware. I have tried to go thru the jailbreak process, and get thru that ok, then have to tether again to boot cydia, but when it comes to unlock, I can only find instructions to unlock if I have modem firmware of the 1.59 ---or higher than 04.26.08. Mine accordinng to the phone, is firmware 03.10.01...so I cant unlock it for a new tmobile sim. Any help is appreciated...