Video not automatically starting

I have added several .swf video files to slides in my project that is somewhat linear. All videos are set to play automatically when the slide begins with the narration.  I also set the videos to have a trigger which allows them to be looped. The video at the beginning of the presentation plays very well.  However, toward the middle the video doesn't begin for 6-7 seconds.  I have checked the clips and this is not in the video clip. It is only happening once I publish.

Any ideas of why this is happening and how I can fix it??

Thanks, Debbie