The step in 1.3.1 is show the query result in interested point with any x and y and in 1.6 shows the query result in interested point after zoom in 2 steps. The result in 1.3.1 and 1.6 are difference because when user zooms in 2 steps, the BBOX will be change. If the BBOX changes, x and y will change because the pixel is changed. The application cannot find the interested point or the same point (x=240, y=260).