I'm running SUSE 9 and got mplayer to work by d/l the libraries and codecs from here
Code:
http://www.videolan.org/vlc/download-redhat.html
then install mplayer.The mplayer gui evaded me for a long time until I found that typing "gmplayer" in a shell bought it up!
If you get jittery playback of DVD's change the DMA setting for your player to "default"