Director Nora Ephron helms her first certified bomb with Mixed Nuts (D) which registers something south of North, east of Ishtar and beyond Heaven’s Gate. This holiday clunker starring Steve Martin is a hodgepodge of throwaway jokes and witless situations involving fruitcakes, touch-tone phone options for the suicide hotline and a Yuletide cross-dresser. This loose adaptation of the French Le Pere Noel Est Une Ordure may spark a ban on imports.