I'm very sorry that you're having problems. How about you try turning off this: http://support-us.samsung.com/cyber/popup/iframe/pop_troubleshooting_fr.jsp?idx=400743
I am having a lot of problems with jerking (jittering?) and blurring on my un46d8000. The problem is particularly bad when watching sports.
I have not changed the picture settings from the manufacturers settings.
Example: when watching golf, when a player is setting up, areas around the club shaft appear to blur. When he swings the picture jerks badly and then the ball appears blurry when in the air. When the ball lands the picure jerks until the ball comes to a stop.
The problems appear to be worse when there are bright colors on the screen. i.e. a basketball team with bright colored jerseys.
I thought this may be a problem with our local broadband company but we recently switching to AT&T Uverse and the problems persist.
I dont see a lot of posts online with similar problems for this model so I'm wondering if I have a defective unit.
I own quite a few Samsung products and this is the first I've had with issues. I'd love to hear if anyone has suggestions on what might be causing this.