WordPress and Facebook FAIL

Fatal error: Call to undefined method Facebook_WP::getAppSecret() in /homepages/45/d401094567/htdocs/wordpress/wordpress/wp-content/plugins/facebook/includes/facebook-php-sdk/class-facebook-wp.php on line 77

Tried setting this up earlier today and got this message. I am completely locked out of my admin page and dashboard. Is there a way to fix or delete this or do I have to drop wordpress and use some other service?

http://wordpress.org/extend/plugins/facebook/