Forgive me old MEP friends. Everyone gets old ... that's inevitable ... Got another question for which I should know the answer. Was rocking along with a two minute project (with multiple files on the timeline). 'Visual Playback' was smooth at first - after a few files were added, (nothing unusual): Wav files, MP3's, MP4's, a mixture of SD and HD etc. developed a stutter and lost mobility of the playhead. The project or pieces can be successfully exported and played back as MP4's but the playhead is stationary. Thank you for your patience ... Mike