In a medium sauce pan, combine sugar and cornstarch. Gradually stir in water until smooth. Add blueberries and bring sauce to a boil and cook over medium heat until thickened. Serve warm with pancakes.
Sift dry ingredients into a large mixing bowl. In a separate bowl, beat eggs until light. Add the buttermilk and melted margarine to eggs. Combine liquid mixture with dry ingredients, mixing together just until the lumps disappear.
Pour 1/4 cup batter onto a hot, grased griddle or skillet. Place 6-7 berries onto each pancake. Cook pancakes until pancakes have bubbly surface (about 2 minutes per side). Turn once.