This one shot would have been just awesome except for the motion blur. It drove me crazy trying to figure out why there was this shaking. The camera was mounted on a sturdy tripod with extra weight added, on a night with no wind, embedded in sand!

Anyway, after eliminating every other possible problem, I must conclude that it was the stabilization in the lens itself. Since I've been turning that off as well as the autofocus, I haven't had any trouble.