I was in Iowa today. I have an iphone and got pretty good coverage. I was in the Carrol area and had full bars. It said ATT on my phone. I had gotten a couple calls but when I went to place one it said that my phone does not allow outgoing calls. what's up with this? any know why? iWireless appears to be part of tmobile I think. I was stumped why the message was given from the carrier. are there no roaming agreements?