[Plugin: WordPress.com Stats] Site Stats Stopped after Upgrading to WordPress 3.0.2.

nicoleinskip, go to Appearance/Editor in your Dashboard, select the Footer template, and add <?php wp_footer(); ?> to it.

where do I put this <?php wp_footer(); ?>
when I go to the editor section in footer?

The wp_footer solution is so common it’s in the FAQ. If you are helping, please consider that first. Cache and cookies are relevant to a very small set of problems and should never be the first suggestion when it is not clear what the user is reporting.

It is very common for a user to upgrade WordPress and make several other changes at the same time. When they see something go wrong, what they remember is the big change: upgrading WordPress. We see this kind of report very often. Never assume that the change reported by the user was the only change.