I was using a version of a click tracker posted some time ago. It seems to have stopped working around 8pm EDT on May 30th (Wednesday), as clicks were not recorded after that time.
img = new Image();
img.src = 'http://www.domain.com/clicktrackerscript.php?ref=' + escape(document.location) + '&title=' + escape(document.title) + '&ad=' + escape(window.status) + '&id=MySite';
document.getElementById("google_ads_frame").onfocus = hit;
Here's the code: