element.style ruining styling

Ok so if you go to my test site and look at the sidebar you will see that at the bottom of the “Popular Coupons” and “Gaming News” box there is a grey line that covers the last line of the white list.

Using firebug I realised that this was due to the following code:

element.style {
    background: none repeat scroll 0 0 transparent;
}

All the boxes in the sidebar use the same css, but it seems when you use an unordered list the background appears white. How can I create a new div for the white boxes so that I can ovverride element.style? I know I can just use !important;, but my knowledge of CSS is limited and even implementing that is proving to be too difficult for me.

I should add that I want to keep the styling of the “Get Connected” and “Get the latest coupons” boxes.

Any help would be much appreciated!