I think you are right about that.
If you can play it with windows media player,
you should be able to play it with BSPlayer too.
Which version of BSPlayer are you using?
I am using version 500 for some weeks now,
not having any problems with any of my divx movies. 8)
If it is a conflict, using codecs packs may cause this,
you might want to remove all of those,
and just install some codecs you need.
I am using this codecs myself,
working great for about 400 movies I have:
http://forum.bsplayer.org/viewtopic.php?p=6173#6173
This also gives subtitles in windows media player,
without interfearring with BSPlayer, which shows subtitles itself.
