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We had this problem on one of our iphones. Found out it was a flaky APP. The QVC app for whatever reason was playing the video stream after we played with it in the background (no sound or video obviously that we saw). When we went back into the APP, it was already playing where it left off without having to load it.

We got a notice real fast that we were to our limit of the bandwidth from AT&T on that line. Got rid of the APP, and no problems since.
 
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