Apparently, something happened with facebook that i cannot like any Facebook page (in ex. http://www.facebook.com/TheSimpsons). You can like such page on a page itself but not via Like button on your website. Even on facebook documentation page (http://developers.facebook.com/docs/reference/plugins/like/) if you put this url and try to click generated button, it will like and immediately unlike it.
Are there any known reason for such behavior or workaround?