I would also suggest turning off any motion smoothers on your HDTV when watching any of the latter-day Treks.
Motion smoothers are designed to make film motion look smoother, and some say it gives film material a "soap opera" effect, making motion look almost too smooth and not film-like.
Even though TNG, DS9, VOY, and ENT were all basically filmed, they were post-edited in the video realm, which is why it's taking so long to upgrade them to HDTV. And it is this video realm which causes problems with motion smoothers on video-edited shows. I've noticed on my TV that the effect is like a sudden jerky effect where something moving will skip back or forwards a frame or two. It's very noticeable on scrolling credits.