I have an older version of Flash so I have always handled video files a bit differently. However, one common oversight when publishing a Flash movie is to detect for the player version when producing the HTML page, but not setting the player version in the Flash preference pane. They are two different monsters. One detects the users flash player version and requires a minimum that you set, the other determines which Flash player the movie is to be played on.
A mind once stretched by a new idea never regains its original dimensions.
- Oliver Wendell Holmes