Hi there, There is a guy at my local mall who says he can do this for $20. Personally I don't want to waste $20 o something that's free. Here's the situation: I am a tmobile user. I have an iPhone 4 running 4.0.1 running 01.59 with Ultrasn0w. As you may know, the proximity sensors are messed up on firmwares below 4.1 so I want to upgrade to a higher firmware without upgrading my baseband AND I also want my phone unlocked. Please if you can help me, leave a detailed response below with what I should do. Thanks in advance!