Too bad your pictures turned out blurry. I guess that is one thing I will have to look out for when shooting fireworks. However, I have been using that same technique of switching to Manuel for the past three years and have never had my pictures turn out blurry. I usually use Automatic focus on the first burst, turning it to Manuel after the camera has focused automatically, and then shoot the rest of the show on Manuel. Of course, I would have to refocus if I decided to zoom in or out after setting the focus the first time. In my opinion, continue to use this technique but make sure to double check your focus often. Happy shooting next year!