Hi Amanda,
I wonder if MediaLab is stopping after the video is because it is an .mov file, which is associated with Quicktime. MediaLab is supported by Windows Media Player. You can show an .mov by selecting this preference in MediaLab, but it still may be the root of our problem. Try converting the video to another format and trying that video. There is a lot of freeware out there (like Any Video Converter) that you can try.