What will it take for Kevin Costner to give a performance again? His new movie, the western Open Range, which he also directed, has a lot going for it - beautiful camerawork, impressive editing, a strong, simple storyline, a marvelously cantankerous Robert Duvall - yet smack at the center is sweet, dear, painfully inadequate Kevin Costner, looking and sounding so uninvolved with his surroundings and his fellow actors that he weakens his entire film. (It took great restraint to laugh at him only once, at his hysterically unmotivated reading of the cowpoke classic "Let's rustle up some grub.") Some will argue that Costner is actually deeply in character, playing an uncivilized man for whom conversation and companionship offer little comfort, but look at him onscreen: His Zen blankness is indistinguishable from a coma, and his "concentration" resembles nothing so much as a somnambulist struggling to stay awake. As usual, Costner is fine with rare moments of fringe comedy - reminding us why we once liked him in movies like Bull Durham and Field of Dreams and Tin Cup - but he's positively deadly in Open Range, and not because of his character's prowess with a gun.