can you figure this out ? i rooted still no tetheting

[keana]

Hello I have a HTC inspire I used the simple one click root I found on this forum by bobby 323 it worked great everything went as planned I have Rom manager,superuser. But when I click the tethering widget or go to the menu and select tendering I get the same message as if my phone wasn't rooted it says tethering is not set up for this sim contact ATT please help me (please excuse misspelled words I'm.using my phone )