As part of my quest to solve the issue of previewing audio files in KDE I have often logged off of KDE an into Gnome desktop and then back again trying to discover what allows the feature to sometimes work in KDE. Usually my machine is on continuously from early morning until bedtime at night. That was the case yesterday when I made my last comment. This morning however started my machine and booted directly to the KDE desktop, ran nautilus, it worked as you say, closed nautilus and shazam KDE was still there alive and well. I have an idea that some parts of Gnome may "hold over" when switching back and forth...this may have created the sometimes scroll over preview of audio files in KDE to work and also the mysterious desktop switching that I experienced yesterday. Thanks again to all who have comment on this thread. I believe that running nautilus from the command line is my best solution to date.