I want to sell my iPhone to buy the 3GS but i have been on the 3.0 betas for 2 months now and went GM today and want to go back to 2.2 to unlock to sell it for more. Is it still possible to unlock after downgrading or is the baseband changed and cant be unlocked? I thought only 3G iPhones couldnt be unlocked after 2.2.1.