Hi I am experiencing probably one of the most annoying errors with my iPhone 3GS. I am running firmware 4.2.1 and had no problems jailbreaking and unlocking it. Everything worked out fine, however, after about 2 weeks my phone suddenly showed the "No SIM" notification. I took out the SIM card and put it back again but nothing happened not even the notification showed up anymore. When I put my SIM card to another phone it would not work either. So I talked to my carrier who gave me a new card and it worked perfectly. At least that's what I thought. Because after two weeks the same thing happened to me (the "No SIM" notification suddenly showed up again). I changed my SIM card three times in the two months and simply cannot figure out what keeps destroying them. Any suggestions?