I just did this last night. I tried using QuickPwn to update to 2.0.2 and failed miserably. I had first upgraded to 2.0.2 via iTunes, and let it update my baseband. Then QuickPwn wouldn't run for me, so I decided I'd restore the old IPSW I had built with Pwnage for 2.0.2 (it was still in my Trash folder). I had to put it in full DFU mode before I was able to load the cracked IPSW, just as I had to when I first built and installed it via Pwnage.