[Plugin: WordPress SEO by Yoast] Stopwords broken

I installed latest WP SEO plugin (1.2.8.5) and stopwords doesn’t seem to be removed from post slugs as advertised. Is this a known issue or should I enable the stopword removal somewhere? AFAIK this should be automatic and enabled by default.

Thanks, Jarkko

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