Hello! We have WPMU DEV SEO implemented and Google Webmaster Tools will not accept it. It comes back with a "URL not allowed" error no matter how many times we resubmit the sitemap. It did at one point work a few months ago, but now we've got big fat x's on everything.
I ran some searches here on the forum, however they all pointed to installing WPMU DEV SEO, which we do have installed.