media player crashing when playin xvid files or dosent sync with the audio

hey guys!

i’ve been downloading some XVID movies in which some plays perfect and some dosent, either it crashes the mediaplayer or the audio dosent sync with the video, with video playing slow motion.

i used the gspot to find out the codec. it said i hav all the codecs which i need but still my problem is not solved.

i tried uninstalling all the codes re-installed them no luck still. i can play the movies which i converted into xvid even without the codec. its so strange

hope to get any help from here!!!

thanks in advance

max