@egg, thanks for looking but not that.

Here is a XDPX15 conventional page that should work in WD7: CSS3 - Fixed Background.xar
The CSS is in he Page code (head).

If you example the index page source, you will find <body class="xr_bgb0"> or similar, which needs to line up with the CSS code
(<style>
.xr_bgb0 {
/* Set background image to fixed (don't scroll along with the page) */
background-attachment: fixed;
}
</style>).

Acorn