Thread:Project:Support desk/MediaWiki horizontal size is too short

MediaWiki 1.17.0 PHP 5.4.8-1~lucid+1 (apache2handler) MySQL 5.1.41-3ubuntu12.10

https://dl.dropbox.com/u/65839275/Public%20Images/wikierror.png

When the browser is shown at half-screen size, items passing the far right have no background. Is there a means to extend the range of the white background?