Samsung plasma TV PS50A550 50 inch and the setting keep changing back to factory?

[JASON_l_l_666]

I have just got that model plasma TV and everytime I set the colour to what I want after about 30 minutes or so the screen goes black for about 2 seconds then changes back to the factory settings or if I change to the AV or HDMI channels it goes back to factory again ,I downloaded the software update for it but hasn't changed anything anyone have any ideas