I have an iphone 3gs ios 4.1 baseband 05.13.04 baseband jailbroken with ultrasn0w . The sim works fine , but sometimes it the phone just gives me a No Service for about 10-20 mins. Tried removing the sim tried reseting network settings tried reinstalling ultrasn0w. But it still gives me no service at random intervals. It works fine most of the time but when it goes to no service i just dont know what to do.