Just recently, when I watch recorded HD programmes, usually they seem to "stick" and freeze every so often, and won't respond. It will almost ALWAYS happen once during a 30 min programme. I have to stop the programme on tivo and turn the TV off and on again and it's usually OK. It doesn't seem to happen with SD recordings, just HD on various channels. Doesn't happen with live TV via tivo.
It's a fairly new samsung telly, the HDMI cables are in properly and I've swapped them round but no difference. All special settings on the TV are turned off such as games mode etc.