1. it would be great, if you would update robots.txt with
so autodiscovery would work - i know that you are informing google and yahoo, but there are many other search engines, that should have known about sitemap
2. there is a problem with html validation with your plugin, as you are using RDF for social and for breacrumb. It occurs with HTML5 themes, what is today's default. It would be better to use microformats if possible.