Thanks for that, it is very helpful. I was able to debug some of the css that is applied and I found that when I go into the STAARNIGHT_Gallery.css file and delete the width setting that is applied by this style it seems to look ok.
#outerWrapper .Body #center_nav div {
width: 839px;
}
You may still need to adjust the left and right margins to ensure that it is centered after you make this update.