BlackBerry won't let me connect to a network, in the U.S

Hoping someone can help me, have just come to the US from the Uk on holiday and for some reason I cant pick up a network on my BB

I know there is a signal as my wife can get one on hers and my BB will find the cingular network it just wont allow anything other than SOS calls

This is the first time ive been abroad with it and my service provider told me It was enabled for roaming, this is my worst nightmare Im missing all my emails and calls and am going to lose a stack of business over this, anyone got any ideas?

thx

What kind of BB and what provider are you with? Have you tried doing a manual search for networks? Go to Options >Network. Change from automatic to manual and do a manual search (if your carrier/sim allows.) Try different carriers in the list if any others come up. If it's still not working then I think you need to call your carrier back. It probably isn't provisioned properly. if it's not provisioned properly then it's possible that you won't get it to work until you get back and on to your network for the provisioning to be able to go through.

Also, I take it you advised your carrier you'd be taking it internationally? Some carrier have an 'extra' option that needs to be turned on for international travel...