Preheat oven to 350°F. Butter and flour a bundt cake pan. Coarsely chop cranberries. Beat sugar and margarine until light and fluffy. Beat in eggs one at a time, and then beat in sour cream, orange juice, vanilla, and orange peel. Sift flour and salt together. With mixer on low speed, add dry ingredients to egg mixture and stop when all has been added. Mix by hand until just combined. Fold in pecans and cranberries. Pour batter into bundt pan, tapping pans on counter to release any air bubbles. Bake about 45 minutes. Cool in pan for 10 minutes and then turn out onto wire rack and cool completely. Dust cake lightly with powdered sugar. Garnish with a few fresh cranberries.