Meanwhile, cook macaroni according to package directions; drain. Drain and slice kielbasa; set aside.

In large skillet, cook bacon until crisp; drain, reserving 3 tablespoons drippings in skillet. Crumble bacon; set aside.

Cook mushrooms in reserved drippings for 2 minutes. Stir in sugar, flour, salt, and pepper; add the 3/4 cup water and the vinegar. Cook and stir until thickened and bubbly. Add kielbasa, macaroni, bacon and parsley. Toss together lightly. Garnish with additional snipped parsley, if desired. Serve at once. Makes 4 to 6 servings.