Why can't an imported QuickTime movie be seen in 'Test Movie' or after being exported as an SWF file?
QuickTime movies can be imported into Flash and exported as QuickTime 4 with a Flash track containing interactive Flash elements. However, QuickTime playback is not supported in the Flash Player.
When playing a Flash movie in the editor, the QuickTime frames can be seen, but there is no sound. Why?
The QuickTime movie is not actually integrated as part of the Flash file. Instead, it is a placeholder that points to the original file. Once a QuickTime movie has been imported, it can be previewed, but sound is not supported.
Which Flash features are supported in the QuickTime Player?
Only Flash 3 features are supported in the QuickTime 4 Player.
Additionally, some features may behave differently when the Flash content is hosted by the QuickTime 4 Player, compared to the Flash Player. For information on feature differences, see Some Flash features do not work in exported QuickTime movies (TechNote 14129)
Why can't a QuickTime movie be played immediately after importing it?
The QuickTime movie must be put into frames of the timeline, just as any other animation must occupy frames in order for the playback head to read it. Insert as many frames on the Flash timeline as exist in the QuickTime movie.
Beginning one frame after the end of the QuickTime content, a placeholder (Figure 1) will appear on the stage in place of the movie.
Note: The shape of the placeholder is determined by the shape of the QuickTime movie.
Additional information
The Flash 4 manual contains other relevent tips on using QuickTime.