[Plugin: WordPress SEO by Yoast] Error with wp class-simplepie.php?

Hi

I get this on my WP dashboard:

Latest from Yoast:
Fatal error: Out of memory (allocated 33816576) (tried to allocate 1245184 bytes) in /homepages/36/d345846105/htdocs/siteprod/wordpress/wp-includes/class-simplepie.php on line 5410

What does it mean?

Tkx,

My host: shared 1and1

Regards,

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