I had my lg gt540 upgraded to android 2.3.7. Everything works great except that whenever I make a connection to a bluetooth device (speaker or car phone etc.), the phone starts to have problem. I can still make or receive call from the screen but there is no ringtone and I cannot hear the other side while the other side can hear me. I can also use the bluetooth to play music through the connected bluetooth speaker without problem. Just the phone is not working properly when connected to a bluetooth device. Any suggestions ?