Hello and welcome to Android Forums!
Because you have rooted I have moved your thread to the appropriate forum.
If you could provide just a little more information, it would allow us to help you better. When you say you had tethering, was it using a feature provided by your carrier or were you using Android's native tethering options? Were you tethering with a USB cable or using your phone as a Wifi hotspot? Fnally, what country are you in? In some countries (U.S. especially) tethering requires carrier plans to be enabled. Rooting may disable them.