1 Set of Banners not Centering.

I have installed JA Teline IV at
http://threeriverspublishing.com/TRP2/
Toward the bottom of the page is a set of 3 banners in the content-mass-bot position.
I have given banners the following css to get them to center.

div.custommodbannersjgClass {
text-align: center;
padding: 0 0 0;
margin-bottom: 5px;
margin-top: 5px;
display:table;
width:100%;
}
All other banners are now centering except the ones at the bottom.

Notice that the banners are not fully centered and that there is a box under the banners that is not full width.
I want that box full width in the content-mass-bot position and the banners centered in that box. I suspect when the box is made full width the banners will be centered.