Downloaded Clip Video freezes

[JoshuaMaiorino]

I've had this happen several times. I'm broadcasting for about 1.5 to 2.5 hrs every Sunday. When I go to download the clip, after about 2 minutes of the video playing, it just goes to a still frame. The audio keeps playing thou. Also, when I watch it back on the website it plays back, but the audio and video are out of sync. Any ideas as to what I can do?