i have successfully installed sm player on fedora 8,but it is unable to run avi mpeg or dat files.in the error message itis showing that smplayer failed to start,and in log it is showing error message as
"mplayer -noquiet -nofs -sub-fuzziness 1 -identify -slave -vo xv, -zoom -nokeepaspect -framedrop -input conf=/usr/share/smplayer/input.conf -stop-xscreensaver -wid 62914572 -monitorpixelaspect 1 -subfont-autoscale 1 -subfont-text-scale 5 -subcp ISO-8859-1 -subpos 100 -contrast 0 -brightness 0 -hue 0 -saturation 0 -nocache -osdlevel 0 -vf-add screenshot -channels 2 /media/disk-2/songs/new songs/vidio songs/A R Rahman - Maa tujhe salaam{BY Impudent}.DAT"
plz anyone tell me what should i do to this problem.

You might need to install the proper codecs. Were you able to play those files before? Keep in mind that AVI is just a container format, and therefore could be anything (probably DivX though).