Twice today I have had the screen go blank. Once while watching ch. 414 (SD) and just a few minutes ago while watching ch. 144 (HD). When this happens all other channels are fine and all of the Dish screen info/menu/guides are fine. The channels have stayed off for about 5 minutes then come back on. Also the audio is out when this happens. I don't think this would be a receiver problem as only one (that I know of) channel goes out while the other ~200 are working fine. Anybody have any thoughts on what may be causing this?