Part of the ad code is not valid HTML 4.01 transitional, and it would be quite awesome if it were.
In the noscript section, there is the info for the image. That url contains "adview.php?what=zone:1&n=" where it should be "adview.php?what=zone:1&n=".
The & should be &
In the noscript section, there is the info for the image. That url contains "adview.php?what=zone:1&n=" where it should be "adview.php?what=zone:1&n=".
The & should be &