Tested on my wife's laptop (Windows 7 Home Premium SP1 64bits OS) and it worked flawlessly!
(This also concerns BS.Player Free installed with its default settings and codecs/filters)
So I'm starting to think you made an error somewhere or the codecs/filters used on your PC are playing a trick on you?
Did you also install BS.Player with all its default settings and at installation did you allow BS.Player to internally install its preferred codecs/filters?
What filters/codecs does your BS.Player use for playback of the file(s) you used to test?
(To find out load the file and then rightclick > Options > Filters > Advanced.
Then click on "source" and on the small +signs in front of the codecs/filters shown to get further info and access.)