I have a 3rd gen mc model ipod touch. had 3.1.3 jailbreak firmware previously on it. earlier today i upgraded to 4.2.1 non jailbroken firmware Im trying to upgrade to the 4.2.1 jailbroken firmware using red sn0w. I set everything up then when its loading it gets stuck at "exploiting with limera1n" and it just freezes there. What can i do? thanks.