hi, i download 5.1.1 on my 3gs and jailbroke and unlocked with ultrasn0w on redsn0w with ipad baseband 6.15. Although the unlock kept rebooting my iphone, i went back to 5.0.1 and downgraded baseband with redsn0w but ultrasn0w still reboots my iphone when i put my sim in. Any ideas? Thanks and cheers