After the TV has been on for about 5 minutes, when you change channel the screen goes blank and the sound goes off. To continue watching you have to turn the TV off and then back on again. After 5 mins or so you also can't change the volume, look at TV guide aswell as change channel without turning it off and on again. This applies to both remote and using the controls on the side. I have tried re tuning it and a factory reset, i've tried checking for software updates - the current version is 2009/02/26_001001. Please help before I end up chucking it out! and not replacing it with a Samsung.
The model is Samsung Sync Master T220 HD