Panasonic Viera TH-42PV7HS Plasma keeps shutting...

Question

frustrating symptoms on brand new Panasonic Viera 42" plasma! tv just turns itself off sometimes without warning or if changing to certain channels. leaves red light flashing for a while then red light goes away permanently so no longer in normal standby mode. any attempts with remote gives flashing green light on tv. manual power off and on restarts tv but auto off again. found during manual power on, keep changing channel on remote till stable picture appears. then use remote to shut down tv - solid red light indicates normal standby mode. then use remote to turn on again, and it works... till next time it happens. but what is technical fault??