In saucepan, mix together corn syrup and sugar. Heat to almost boiling, stirring constantly. Remove from heat and add peanut butter. Stir until well blended.
Pour cereal into large bowl. Pour hot peanut butter mixture over cereal in bowl and gently toss until well mixed and cereal is coated. Spread in ungreased 13-by-9-inch pan, leveling top and pressing into corners. Sprinkle butterscotch and chocolate chips over top, distributing evenly. Place pan in warm oven, then turn oven off. Let pan sit in oven with door closed for about 10 minutes so chips melt. Remove from oven and spread melted chips over top of bars. Sprinkle with nuts. Cool completely, then cut into 20 (21/4-by-21/2-inch) rectangles. Then cut each rectangle in half to make 2 triangles. Makes 40 bars.