I've heard from several sources that defragging a drive with thousands of media files on it can result in noticable glitches and missing frames upon playback. I wouldn't give too much credence to any of the sources, but I'm nonetheless reluctant to go ahead and defrag. I have a 108 Gb drive almost full with music and video files. I can think of little worse than having all those files permanently screwed up, but the drive is heavily fragmented and is becoming atrociously slow to respond. Is there any veracity to those claims? Can a routine defrag leave glitches in audio tracks?