BS Player would be an awesome player if it worked

[BSPeter]

Well you guessed wrong! No problems here. Surely not with AC3 sound, which is - like you say - rather standard. What type of video are we talking about?
When installing BS.Player did you allow it to internally (i.e. for exclusive use by BS.Player) install its preferred codecs/filters?
Any problems which may be UAC-related?
Did you install without changing the defaults?
What filters/codecs (especially source and audio related) is BS.Player actually using when you play such file?
To find out:
with a file loaded (rightclick >) Options > Filters > Advanced
(For further info and access you may have to click on the + signs in front of the filters/codecs).

P.S.:
BS.Player-Pro users are entitled to get direct (email) support from BS.Player team. You can contact them here. Please let us know when you contact them.