Hey Folks, Brand new here. I recently got a 3GS from a friend who upgraded. AT&T won't unlock it unless its active so..... been searching and shuffling around on the line, and need to clarify a few things. I have 5.1.1(9B206) BB 05.16.05 model MC 135LL Serial **943****** I have been struggling to unlock 5.1.1 with the BB or even downgrade the BB. And, it appears the newest versions of Ultrasn0w only work with version 6.**, so.... I am thinking of upgrading to iOS 6.1.3 (think that is the latest version telling me I can update to), then downgrade it to 6.1.2 and downgrade the BB so I can jailbreak and unlock. I am trying to install a Net10 SIM card, so the unlock is more important. Anyone got thoughts on this? Problems? Different suggestions? Need to get done soon so I can cancel my contract with Verizon before the next billing date next week. Thanks for checking the thread.