the plugin has a few small mistakes.
country_name should be country-name (notice the -, in stead of the _ ).
street_adress should be street-adress
postal_code should be postal-code
fax_number should be fax-number
besides, it's not clearly stated that "Facebook Page ID:" is NOT the same is "Numeric Facebook ID:".
also, the plugin doesn't always translate the "like" button, for example on 1 of my sites (which is in dutch), is shows "like", while the dutch word should be "vind ik leuk".
even when i used it in a german and french website, the "like" button wouldn't translate.
perhaps something that could be fixed in the future.
all together, a nice plugin.
just missing some details.