Richard... just so your problem thread... sorry I've been OFF FT for a week due to travel/work...
Is this on T-Mobile's network or a roaming agreement? Has T-Mobile opened a trouble ticket... If they've done nothing since now, let me know via email and I can see if our T-mobile rep can ping their network ops on what the problem is.
So far I've been in Europe with my US T-Mobile 6230 Blackberry with no issues for the last week. So may just be an issue related to a local network problem?