My incoming calls

Hello,
I have a T-mobile G1 and I don't know what happened but all my calls that I receive show up as a private call! Like I would go to contacts and call some one who is saved in there and ythe call would show up a private. When some one calls me it shows up private even if it is a saved contact? If there is someone out there that knows what my problem please tell me what to do to get my phone back working right!