Believe me, you are not alone in having jitter/stutter/frame skipping problems with Auto Motion Plus on your Samsung. I have the same problem on my brand new LN40D630. And an internet search on this topic reveals that this is a common problem. It is obvious to me that Samsung has not yet mastered this frame interpolation technology, and worse yet, they seem not to care about doing anything about it as they keep churning out new models that have exactly the same problem. By contrast, my LG LED TV has their own "TruMotion" frame interpolation feature, and it works perfectly, albeit, with soap opera effect, which is expected. But at least, my Samsung has a great picture with AMP turned off. One other thing I would mention is that the frame skipping only seems to be an issue with HDMI, as I do not notice it when watching OTA with a rabbit ear antenna. I am going to experiment with component cables next to confirm my suspicion that this is an HDMI compatibility issue.