Hi. I recently updated to 7.1.2 via OTA. Since then any cellular activity puts the phone into flight mode and it's impossible to use it. You make a call, cut the recieved call, turn on/off cellular data, restart the phone... IT AUTOMATIXALLY GOES INTO FLIGHT MODE. This is a very serious bug, especially in case of emergency, and make the phone utterle useless. Please get a fix ASAP.