[Plugin: WordPress SEO by Yoast] Spanish translation not working

WordPress version: 3.4.1
WordPress SEO version: 1.2.8.2

I did this: Upgraded from 1.7 to newest

I expected the plugin to do this:

Instead it did this:
The spanish tranlation is not working properly. Many texts are in white and even the Titles&Meta option has dissapear because the text does not exist.

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