I'm still plagued with constant failed calls and am reaching the end of my rope. I've tried doing a restore but no luck there on solving the issue. Some believe that the SIM card could create an issue, which I might look into this weekend. My question: Can either AT&T or Apple connect my phone or view my call log and determine the number of failed calls that I have? I feel like this information would make the exchange/fix process go much smoother. I'd say my failure rate is somewhere between 25-35% which is unacceptable to me. Of course, the other iPhone user in my household isn't experiencing these issues which really makes me think it's my phone and not the network.