Currently Being ModeratedNov 10, 2012 7:03 PM (in response to Dhavala)
Try Here > http://support.apple.com/kb/TS2756
Perhaps... Reseting Network Settings
Currently Being ModeratedNov 21, 2012 1:18 PM (in response to Dhavala)
This is from another apple user but fixed my issue.
I figured out the issue. Turn off FaceTime over cellular, restart the iPhone and the tethering works. Somehow turning on FaceTime over cellular breaks tethering.