Extended Disply Problem

[stublack]

For security reasons I changed all my MP3+g songs to MP4. I also added a watermark (which might be the problem) to each song. When I play any song with the window on the laptop it plays just fine. When I move the window to an extended screen the video is garbled for the first couple seconds and then it play fine never out of synch. Is there something I can do to fix this??