I got a SIM Failure message today. I tried to power cycle the phone and the problem went away for about 10 minutes and then came back. I have also tried to reset network settings and also to reset all settings but the error still persists. I've searched the forums and saw that people were experiencing similar issues with the iOS 6.0.1 update. I'm running iOS 6.1.4 and have never had these issues before. Does anyone have any advice?