You might try calling to customer service to speak with technical support. The settings might be setup in the Motorola phone but there are some additional settings that need to be configured by Cingular through the technical settings in the billing system. Your internet transport settings in the Cingular system might not be configured.
I recently purchase a unlocked motorola razor v3 phone and had a prepaid sim card from tmobile and works great. Now i activated the phone with Cingular and everything works fine except aol instant message and the internet.. I went to a Cingular store and the sales man configed the phone for me and the internet worked for the first day and now it will not work but my mms and text messaging are working fine. But aol instant messaging will not work at all so if anyone has got it to work or has the sofware that is needed or the configuration that is needed please help me...

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic