So this past Saturday my N9 was acting really weird and I thought it was the sim card since i made it to a microsim myself. The signal kept going down to zero when I am suppose to have all bars. I have AT&T btw. And it would come back after I turned the phone off. I could receive texts and calls but not send anything because I always got an error. Thinking there was a problem with my sim card, I went to AT&T and got a new microsim. I put it in and it worked fine but when I went to sleep the same thing happened. The signal was completely zero and it came back after I put it into airplane mode. As anyone else experienced this? Is there a fix for this situation?