When trying to connect to my browser, I get the error message: "Unable to connect to the selected Mobile Data Service, please try again later. If the problem persists please contact your administrator."

I reset the TCP to the following, removed the battery and restarted the computer with no luck:
APN:WAP.CINGULAR
Username:
Password: CINGULAR1

I'm wondering if having AT&T as the new provider makes a difference. Any ideas for how to get the browser working?