WillieO on "[Plugin: WordPress SEO by Yoast] multiple h1 tags"

I am getting a warning in Bing webmaster central saying I have multiple h1 tags. This is occurring on all my pages and posts. Even when I removed the %%sitename%% in the titles and meta boxes this happens. Has anyone run into this?
Thanks

http://wordpress.org/extend/plugins/wordpress-seo/