Your div (backgroundextra) has 800px height. So has the image. Thus, which bottom corner (by the way, should be right bottom, in this order - but I see that you have written correctly into your site) do you expect? You could have equally used right bottom or center bottom or simply right, and get the same result, because both the container div and the image have the same height.
ok so all you had to say was just remove the height of the div....lol ty, however when you go to the page you have to scroll down to see it, if its like in a resized window, he should be there and be scrollable, i dont knowif this is possible