www.hpc.esu7.org/website/test/test.html

Can anyone look and tell me why this won't center? Thanks.

For me, it is centered (IE8).

You have an opening <div id="centered"> and a closing </div> to match, and views fine here.

My guess would be that the dimensions of your background object are 962x1076 and at the same time you use 800x600 as your project resolution.