I tried to unlock my SIM earlier this week and gave up after failing a few times using different tools and guides. I did a reset/restore yesterday and thought things would go back to normal.
Updating to 1.1.1, I got this message in iTunes and the phone is showing a "incorrect SIM" message, even though I'm using my AT&T original SIM.
Just returned from the AT&T local store with a new SIM on my account and the phone and iTunes still show the bad SIM message. I'm going to vote "bricked" at this point.