Hi all. I have a 2.0 firmware unlocked iPhone that began life with the 1.1.2 firmware and HW unlocked (about 5 hours before the software unlock was released!).
I've experienced two problems since upgrading to 2.0.
1) I had been playing on the phone for a while. I pressed Mobile News icon and the phone resprung back to the springboard and I had a "NO SIM INSTALLED" message, no connection. It was scary, as I was out at a restaurant and thought my phone was suddenly dying! Multiple reboots and it didn't work. Eventually after 15 minutes I regained connection and the message just went away.
2) I received a call and slid the slider to answer. When the slider got to the end, instead of answering the call, the phone froze at that point. The phone still was vibrating until I presume the person hung up, but the entire time my phone was stuck on the 'answer' screen. Only happened once so far.