Perhaps check what is selected at "For AC3 decoding use:" under
(rightclick >) Options > Preferences > Audio
Maybe re-register quartz.dll
http://forum.bsplayer.org/viewtopic.php?p=15068#15068
:?
P.S.:
BSPlayer version?
What codec/filter is used by BSPlayer for playback? (see last line of item
(3) of my
Help2Help-post)