I have an iphone 3gs running 3.0.1. I did all the steps to activate tethering and mms. All seemed to work well, under settings, general, network appeared the tethering tab. When I switch it to on nothing happens. Meaning I don't get that blue bar across the top that says the phone is tethering. Also I have AT&T carrier 6.0 installed. Any help would be greatly appreciated.