Hey, the string won't get translated if you provide false as the first parameter, and then an absolute path to load_plugin_textdomain
in smcf.php at line 37 I've set
function init() {
$smcfdir = dirname( plugin_basename( __FILE__ ) );
load_plugin_textdomain("smcf", false, $smcfdir . "/lang/");
and now files in the /lang subfolders are successfully loaded
http://wordpress.org/extend/plugins/simplemodal-contact-form-smcf/