Typo Error in fixed:
fixed:
function lang_get_defaulted( $p_string, $p_default = null ) {
if ( lang_exists( $p_string,$p_default) ) {

Following is the new implementation for the method:

function lang_get_defaulted( $p_string, $p_default = null, $p_lang = null ) {
$t_lang = $p_lang;

if ( NULL == $t_lang ) {
    $t_lang = lang_get_default();
}

if ( 'auto' == $t_lang ) {
    $t_lang = lang_map_auto();
}

# Now we'll make sure that the requested language is loaded
lang_ensure_loaded( $t_lang );

if ( lang_exists( $p_string, $t_lang ) ) {
    return lang_get( $p_string );
} else {
    if ( null === $p_default ) {
        return $p_string;
    } else {
        return $p_default;
    }
}

}