After lots of trials this is the way I managed to get it, in order to avoid that awful black at the right of the page.

Just be sure you have the url of the image you want to use for a background.

Right after the line that tells the browser to use the CSS within the document:


ADD this:

.community { background-image: url("http://www.WHATEVER.WHATEVER") !important; background-repeat: repeat !important}

And remember you have to insert it before the close of the style:


Hope it helps.