xvid encoded movies normally have an .avi extension (not .xvid).
Maybe it is related to BS.Player therefore not recognizing these files as video files. Try as follows:
(rightclick >) Options > Preferences > General > File types
Now type "xvid" in the white box above "Add extension" and then click "Add extension", at which time you will be prompted to indicate the mediatype: select Video.
Close (maybe also Exit and restart).
Does that help?
