You could also try switching on Triple Buffering on the Control Panel if you haven't already.
Which card do you have, again? (getting a few threads/players mixed up now, sorry) The higher end ones will have stutter if the game camera is moved around quickly or if you are playing at high speeds (more than 1-Normal). You could turn down Detailed Lots to 2 or so, and Water/Reflections to one of the middle settings. Other than that, there likely isn't much you can do about it if it's otherwise tolerable.