just be patient during the process. I just did it yesterday with the modmyiphone.com tutorial, and, following the instructions correctly had no problem.
my experience is with the firmware version 1.0.2. Not sure if this helps you.ahh soo much instructions... how many hours does it take to unlock... ok now the question.... when you unlock do you leave the AT&T sim card in the phone or did you plug in your Rogers/Fido from the start?