So my wife recently upgraded to the iPhone 4 and we planned on giving her old 3GS to her sister to use on T-Mobile network. We have done this in the past with our old iPhones and I even have my iPhone 4 (4.3.3 w/ 4.10.01 baseband) jailbroken. Anyways, during the wipe process I could not get the 3GS to restore to anything but 4.3.4 w/ 5.16.02 baseband. I have been trying for days to get it to restore to something else (4.3.3 and 6.15.00) so that I can unlock for her sister but to no luck. From reading everything, and receiving the "This device is not elgibile for the requested build" error I think I am SOL. I need a break/unlock that is reliable and untethered. Suggestions? iPhone 3GS, 4.3.4 Firmware, baseband 5.16.02 (or whatever the latest is). Would love to downgrade to 4.3.3 or 4.2.1 but everything I have tried (snowbreeze, pwngetool, redsnow) has failed with the same message.