Due to his leaving the Director's Guild to co-direct SIN CITY with the comic creator Frank Miller, helmer Robert Rodriguez has stepped down as director of the Paramount adaptation of the first book in Edgar Rice Burroughs' 11-book JOHN CARTER OF MARS series, A PRINCESS OF MARS, reports IGN FilmForce. Rodriguez couldn't stay on MARS because Paramount under DGA guidelines can't employ directors who are not members of the guild. Despite not having a director, Paramount still plans to go into production on the film next year.