Hi,

I had the same problem. I'm on the unlimited talk/text/web 79.99 plan... I was using a BB previously and had BB data and internet when i got my n900 last week, i switched the SIM and i wasnt able to surf through 3G...

I Called TMo and talked to their level 3 techs... Dont bother trying to do it yourself... They pushed the provisioning of a similar smartphone to my n900 while i was talking to them; it works beautifully now.