I was importing video yesterday to add to a previous file. The video imported just fine and then an extra half-hour was required while the computer rendered it (I think that's what it told me it was doing). By the end of the half hour, I had the spinning beach ball and had to force quite iMovie. Now when I try to open the file, the new video shows up as blank (grey) film, although if I click the mouse in this large area, I can see the video. The problem is that every action I try to the file--whether it is to the previous normal video or to the new grey video--required massive waiting time with the spinning beach ball. Any thoughts on what I might do to get this file working normally again?