Dear all, I see you all are doing an excellent job. It seems that NET10 and Cingular also fooled me. I have been using the SIM card from NET10 for a while and because I was not satisfied with their service I decided to switch to Cingular. I asked them about compatibility and I was "assured" that I won't have any problem. I was unpleasantly surprised today when I received my Cingular card to see that the "SIM is not valid" . I would highly appreciate if someone could help me with my Nokia 1600. IMEI: 010972004406326 Firmware version: N1600B V5.01, 03-24-06, RH-65, (c) NMP, Language: UB Nokia: 1600 IMEI: 010972004406326 Network: the phone is locked to Cingular Country: USA Thank you!