I'm about to buy an iPhone 4 running 4.3.5. Does it matter what baseband it is (can't all 4.3.5 basebands be unlocked, assuming its a GSM (AT&T) iPhone 4?) Currently unsure of the baseband, but when I find out, I'll let you guys know. Next question... assuming I can get it unlocked at 4.3.5... Is it possible for me to upgrade it to iOS 5? Isn't there a way to "preserve a baseband" or something? Thank you in advanced!