 Originally titled Grey Night, the title was changed for some film festivals  to Grey Knight.  This is the directors cut of the film.  Allegedly, after  some previews (most notably one for USA network executives), the producer  (Brad Krevoy) was led to believe the movie was "too artsy" and ordered it  recut.  The producers cut is known as The Killing Box.  Both versions are  sometimes known on video as Ghost Brigade, though the laserdisc Ghost Brigade  is Grey Night with only its title changed.