That sound like a 1080i issue. If you have a cable or satellite box, most default everything to 1080i. That includes 720p60 programming such as sports and networks like ABC/Fox/ESPN and others. Doing that will create stutter at time. If your box allows you to set it at native, switch it to that. Then 720p60 will be at 720p60 and 1080i will be at 1080i60. Forcing progressive scans to interlaced scans causes issues.I have everything off except Real Cinema.
The stutter is semi random. The one somewhat unifying thing that causes the stutter seems to be when there is a large digital display with movement around that display, or some kind of complex background with movement in the foreground.
Family Feud. When Steve Harvey goes over to the families to ask a question and there is a shot of the scoreboard in the background, the movement of Steve and the contestants will often stutter. Happens quite often.
Watching a Basketball game. When a player is at free throw line and then a score or some type of stat display comes up, it often stutters. Not when the game is actually going on, though. Only during the particular free throw line camera shot does this happen.
SNY, in particular, but other news or sporting news shows can trigger it, but they are rare. SNY is semi reliable. When watching the Knicks postgame show (I know, I'm a masochist) and the two broadcasters are on either side of the digital display in the background and the shot also contains the display on the desk that they are sitting behind, it stutters.
It's basically like the chip in the 6 Series is so crappy that it can't handle displaying movement and complex graphics at the same time, is the best way to describe it.