I too am very frustrated as AT&T is saying it is the Apple software of the hardware. I have replaced the phone with a new one and still the same problem of tethering not working. Maybe it is time I go with an Android phone. I come from a long line of Apple devotees. We have 8 iphones in my immediate family along with Mac Pros, laptops and iPads. I just want it fixed and they both are saying it is not them. I personally believe it is a software issue!