My friend just got the iPhone 3GS and gave me his old iPhone 3G. There is no SIM card in it. It has worked fine until I restored and did the 3.0.1 update. Now it has a message on the home screen that says "No SIM Card Installed" and to put in a SIM card or a PIN. It won't let me do anything other than make an emergency call. How do I fix this without getting a SIM card?