[Plugin: WP-Gravatar] 404 error when clicking on ‘Gravatar’ in admin menu

When I click on the ‘Gravatar’ link (https://mysite.com/wp-admin/gravatar) in my admin menu, I get a 404 error. Any advice on how to fix this?

FYI: I’ve been using WP-Gravatar for several months [this is not a new install] but I just upgraded from WordPress 2.5.1 to 2.6.2 and I have the latest version of WP-Gravatars installed.

Thanks!