Bsplayer plays avi video file, but no sound! plz help

[DeadlyTiga]

I have a .avi file with this audio codec:
0x0055(MP3) ID'd as MPEG-1 Layer 3

Gspot says, that this codec is installed, the windows mediaplayer plays video and sound but my BSplayer only plays the video.
The video Codec is xvid.
I have the BSplayer 1.21 build 816
so what can i do, to let bsplayer play the sound of this file too...i hate wmp!
thx 4 help

edit:
i found out, that when i start powerdvd i cant watch the movies with bsplayer too, and bsplayer plays the sound while i stop powerdvd playing, but let it open. When i close powerdvd, also bsplayer stops playing sound! i have this problem with every video file now 8(

[adicoto]

Try to install an AC3 filter and an alternate MPEG1 layer 3 decoder, such the one in DivX 3.11