I'm sorry to hear that you're having this issue.
That option may be available by pressing the TOOLS button while streaming. Is this using Netflix through the TV, or a connected player like a Blu-Ray or game console?
We love our Samsung LN46C650 flat screen but very much disliked the default Auto Motion Plus feature as it makes motion pictures look like a soap opera video recording. After some digging, I figured it was the Auto Motion Plus. I disabled it and the picture turned back to normal - beautiful. But for some reason, streaming videos have Auto Motion Plus as default and turning off the Auto Motion Plus does not turn it off for streaming. All of my Netflicks movies look like soap opera video recordings.
Does someone know how to turn off Auto Motion Plus for streaming videos as well? I am considering buying another Samsung but will not buy one unless I can turn off this feature for streaming video.