Double check that. I think if your baseband from iOS 4 is preserved, you actually can use GeveySim. I know that at least ultrasn0w will NOT work, however.jailbreak it with redsn0w 0.9.10b3 and you will have untethered jailbreak. However, you can't unlock it at all.
never mind, a hard reset fixed this problem.any idea why mail.app wont display anything now that ive jailbroken?
and why cydia is a blank icon that wont open?