og:image and gravatar

Is it the social ring widget that also writes the facebook meta tags? if so, is there a way to prevent it from using the gravatar service to fill the facebook og:image tag? gravatar always points to avatar images that it finds somewhere. The effect is that if I post a WP page on facebook, the preview image is always the avatar image of the page author – or an empty image if gravatar fails to find an image. What I would prefer: that the facebook preview image would be an image taken from the images on the page that I want to post. Not entirely sure how to do that. Ideas?

http://wordpress.org/extend/plugins/wordpress-social-ring/