Place meatballs in crockpot. Drain pineapple tidbits, reserving syrup. In medium saucepan, combine pineapple syrup and cornstarch until cornstarch dissolves. Blend in pineapple tidbits, brown sugar, water, cider vinegar and soy sauce. Cook and stir over medium heat until thick and bubbly. Pour sauce over meatballs and let simmer on low 2-3 hours, or until heated through.