I just recently upgraded from REV 5523 (0.7.9) to REV 5568 (0.8.1) via the Builder Wizard. Now when I preview my project in the project monitor, the video in some of the clips freezes while the audio plays fine. It also renders the same way. When I physically drag the cursor through the clip on the timeline, the video moves normally but if I "play" it, the video freezes as if the clip were a still image. I can't figure out why some clips freeze and others don't. A few bouts of trial and error proved unsuccessful. Don't know if it's my installation of Kdenlive or Kdenlive itself. Does anyone else have this problem? This problem is present only in my REV 5568 and not in REV 5523. Both Revisions use MLT 0.7.1 which was installed automatically with the Builder Wizard. Any help would be appreciated.