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Thread: Jailbreak 4.2.1 and unlock
05-28-2011, 12:03 PM #21iPhone? More like MyPhone
iClarified - iPhone - How to Jailbreak Your iPhone 4 Using PwnageTool (Mac) [4.3.3]
I didn't find any mention on a switch for baseband preservation, so I assume it's done in every case. Hopefully someone else can confirm.