I have installed the plugin and it works OK but the localization.
This is the situation:
1. In the wordpress/wp-content/plugins/contact-form-7/languages directory I have the following files (modified by myself with poedit):
2. In the wordpress/wp-config.php file I have the following line:
define ('WPLANG', 'es_ES');
3. The subscription form shows the text in english, not spanish :( (I mean "Your name", "Your email", "Subscribe me"