Are you sure video compression format is DivX? You can check using e.g. GSpot (See the 2nd item of my "Help to Help"-post; link at bottom of this post).
What version of DivX codec do you have installed?
(You can check through [Start] > Programs > DivX > DivX Codec > Decoder Configuration Utility)
If it isn't latest version (5.1.1.) I would suggest to update first.
(See
this post for a direct link)