/* NOTE:
   Unfortunately, vertical centering is a notorious weak spot of CSS. Vertical
   centering is only possible for content of TD's. Don't ask me why, I disagree
   strongly, but the problem is there and should be solved.
*/

table { width: 100%; height: 100%; }
td#bannercontainer { vertical-align: middle; }
#banner { margin: 0 0 0 0; text-align: center; }