Bullets corrupted on Categories widget

Thanks so much for releasing Montezuma! I've been looking for a sleek new look for my personal Web site, and I've finally found it

I use Piwik to track visitors. Ever since I inserted the Piwik tracking code in the header.php sub template, the bullets on my sidebar's "Categories" widget don't display properly. You can see it here: http://www.js-wordsmith.com.

What should I do to fix this?