Heat a small saucepan over medium-high heat. Coat pan with cooking spray.
Add garlic to pan; cook 30 seconds. Stir in preserves and the next 4 ingredients (through dried oregano); bring mixture to a boil. Reduce heat, and cook for 5 minutes, stirring occasionally. Stir in 1/4 teaspoon salt and 1/8 teaspoon pepper.
Sprinkle chicken with the remaining 1/2 teaspoon salt and 1/8 teaspoon pepper.
Combine chicken and 1/2 cup preserves mixture in a large bowl; toss well to coat. Arrange chicken on a grill rack coated with cooking spray; grill 5 minutes. Turn chicken thighs over, and brush chicken with the remaining 1/4 cup preserves mixture. Grill an additional 5 minutes or until done.
