GameHaunt on "[Plugin: WordPress SEO by Yoast] Title Problems"

WordPress version: 3.5.1
WordPress SEO version: Version 1.4.4

I did this:
Enabled Force rewrite titles
%%title%% | %%sitename%%

I expected the plugin to do this:
%%title%% | %%sitename%%

Instead it did this:
http://i.imgur.com/Ki6WzrS.png

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