I've been watching TV via my DVD recorder for a couple of months now, but in recent weeks it has suddenly begun turning off without warning. It happened three times this evening. Is this a heat problem? It happens during the day and night, but as it is summer here now I guess it could be heat related... Should I rather not have it on all the time (when the TV is on)? Or could it perhaps be something that should be fixed under warranty? Any sound advice would be appreciated, thanks.