I'm using Nero 7 ultra edition and Nero Vision 4 for the first time. Just trying to edit a movie. I initially played the file in Nero Showtime. Worked perfectly. After I added the files to Nero Vision 4, the preview will only play for a few seconds. I exported just to see what would happen, and the movie was only a few seconds long. What am I doing wrong? This is driving me crazy! Thanks.