BSplayer gives you that message because you don't have the proper codec installed for that kind of files :)
You need the proper codec (DivX 3.11).
Take a look at these posts:
http://forum.bsplayer.org/viewtopic.php?t=6929 http://forum.bsplayer.org/viewtopic.php?t=6613
Furter check also
adicoto's
List of codecs
Bye
Did you read BSPeter's "READ THIS FIRST BEFORE POSTING" post AKA Help2Help (link in my signature)