I have had a lot of trouble with the tethering on my iPhone. The first time I set it up, it worked wirelessly and I was pleased. The next time I decided to use it, it would not show up. I reset the settings and tried to use it again, nothing.. Next, I tried with the cable attached. I got the blue bar on top saying tethering was up, but no luck. I read the troubleshooting guide on Apple's website and I still have no service, even though the blue bar is saying the phone is connected, the Network and bluetooth preferences say it is not connected. Anyone who can give me some data or advice would be appreciated.

Thanks