I am using final Cut pro 6 to edit a feature length documentary. I accidentally did something to a clip in the time line as it is video black in the final Cut pro timeline. The clip that it references in the capture scratch is the video file I want, picture and sound.
Check the Opacity in the Motion Tab. Sometimes when you are adjusting audio levels in the timeline using the rubber-bands you can accidentally pull down the opacity of a video clip. It then becomes completely transparent and would show up as black if there are no other clips under it.