video clips disappear when burn to dvd

[aliceK]

Hi. I'm new to the boards and relatively new to PS. I've been building slideshows with a mix of photo and video - last one I did I upped the size of the video clips to HD to improve the quality of the image. When I burned to dvd, however, one of the video clips cut out half way through; two others just weren't there; and the last one was just fine. Does anyone have any suggestions how I could fix this? Thanks.