Neither page is resizing the image to the viewport resolution; if you make the window smaller, about 1000px wide, and drag it wider and narrower, the image will disappear out to the left and right in both pages. I don't think you can get a background-image to resize. It has a fixed size and you can set options to fix it to the center so that both sides get cut off in a small window, or set it to the left so that only the right side gets cut off. One image is 1600px wide and the other 1230px wide, so you may be seeing some different centralising in different windows, but not resizing.
The background-position property is described here:-
http://www.w3schools.com/css/pr_background-position.asp
If you want the image to resize in any viewport resolution, see this example
http://www.wickham43.net/backgroundfull
xible.html
drag the window wider and narrower and see that the sides are fixed to the window edges and the width and height adjust according to the window size.
The example uses a normal image, not a background-image, which is positioned with position: fixed and other content shows on top because of z-index: -1; and the image stays fixed when scrolling. Edit: since your images have a central section for content, you will have to use a flexible or percentage width for the content so that resizes as well. It could be complicated.
IE6 does not operate position: fixed so position: absolute has to be used, so the image scolls up and down with the content in IE6 although it does adjust to the viewport width in the same way.
Last edited by Wickham (December 23, 2008 6:12 am)