I can't speak for anyone else, but I'm still very content with a 1024x768 screen resolution on a 17" CRT monitor. There are many people still out there that prefer less resolution equating to a more compressed layout.
The main page picture is 640px in width. A rough note to be to include 150px for each side column and miscellaneous for assigned borders. So, the layout width would have to be over 950px wide to allot room for that main page picture.
So, you can either resize that image or adjust to fit in the stylesheet.css:
Code:
#mainWrapper {
text-align: left;
width: 750px;
vertical-align: top;
}