Actress: 9/11 our fault By MAGGIE HABERMAN DAILY NEWS STAFF WRITER Maggie Gyllenhaal Actress Maggie Gyllenhaal, star of a new flick about the aftermath of 9/11, believes the United States "is responsible in some way" for the devastating terror attacks. Gyllenhaal, 27, made the comments at the Tribeca Film Festival, where her new movie "The Great New Wonderful" - which has a plot centered on the destruction of the World Trade Center - premiered Friday. "I think what's good about the movie is that it deals with 9/11 in such a subtle, open way that I think it allows it...