See - I think it's something else entirely.
I notice on my P900 or 6600 that the GPRS connection will not be available sometimes. It says it is - but its just dead.
I think it is a coverage issue because T-Mobile doesn't have nearly enough spectrum in my market to keep up with the Junior OG's and their SideKicks and the BlackBerry crusade.
Could be T-Mobile's infrastructure sucking though, who knows.