I was wondering if anyone else has a problem text messaging certain numbers with Cingular. I have a V400 phone and I was trying to text my friend who has a T-Mobile phone with a 347 area code (NYC). I keep getting a message that says "Unidentified Number...etc". I know it's the right number because he can text me and we have no problem calling each other. It's just the outgoing texts on my end. I can also text him with no problem from my AT&T phone...any ideas??