Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Mine does too, I think it may have to do with the firmware that the carrier can send (like with other phones) or has to do with GSM identity code, and may be different when roaming, so it will show you when you are on a CinciBell or AllTell.

TEG
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.