I have noticed that sometimes when I record video, it has a high pitched buzzing noise. For example watch the video below. http://www.youtube.com/watch?v=7BLer5rWhpM You will hear the high pitch buzzing noise and then at 7 seconds into the video it is gone. It is totally random when it will happen and was wondering if anybody else has seen/heard this? The video was uploaded from the iphone via the YouTube upload feature on the phone.