hide_empty on default theme not working

At first I thought is was a program with the themes I was using. I’ve installed them through just searching the WP theme database. So, I decided I’d try this on the default WP theme.

Originally there is the following:

<?php wp_list_categories('show_count=1&title_li=<h2>Categories</h2>'); ?>

I changed it to:

<?php wp_list_categories('show_count=1&title_li=<h2>Categories</h2>&hide_empty=0'); ?>

On the sidebar it still does not show the empty categories. I modified the code by the theme editor. Just to see if it was maybe not updating I manually modified the code in Notepad++ then FTPed the file to my website. Still no go.