OMG ..... you hit the nail on the head. I just upgraded to f16 KDE, and it took me 4 days to get around to fixing the video playback. Video playbeck would crash my X from vlc and dragon, but changing video output to glx fixed my problem.
.........Just a note, I have a Nvidia gt9400 video card, but with this install I did not install the Nvidia drivers
.... I use Fedora 16 KDE 64bit
Thanks a lot!!!!!!