Preheat oven to 325*F Grease and flour 10" tube or 12-cup Bundt (R) pan. Sprinkle nuts over bottom of pan. Mix cake mix, pudding, 4 eggs, water, oil and 1/2 cup rum together. Pour batter over nuts. Bake 1 hour. Cool. Invert over serving plate. Prick top. Drizzle and smooth glaze evenly over top and sides. Allow cake to absorb glaze. Repeat until glaze is used up. Glaze: Melt butter in saucepan. Stir in water and sugar. Boil 5 minutes, stirring constantly. Remove from heat. Stir in rum.