If I set useCssRight to true,I get wrong top value

 ` <Align target={this.getTarget}
          align={{points: points, offset: offset, useCssRight: true}}
          onAlign={this.onAlign.bind(this)}
      >`
I met some strange  problem,If I dont use 'useCssRight',the position defaults to using left and top in poistion absolute,If I use that, it became use right,but get wrong top value