The vertical scrollbar is affected by moving horizontal scrollbar

Hi all, When I draged the horizontal scrollbar to the end, but suddenly the vertical scrollbar moved automatically. You can try it here. http://ui-grid.info/docs/#!/tutorial/Tutorial:%20213%20Auto-Resizing . First, scrolling the vertical scrollbar to the end, then you can see the last id is 499. Second, draging the horizontal scrollbar to the end. Then the vertical scrollbar is affected. Drag the horizontal scrollbar to the begining, now the last id you can see is 496.