You didn't mention version/build of BS.Player used!
However, known and meanwhile solved issue:
http://forum.bsplayer.com/bug-report...html#post40571
P.S.:
I take it you mean you press "C" to
pause (Note: Spacebar will do as well!)
Then perhaps select the exact image with arrow right arrow left
and then press "P" to make the screencapture!