Some interface strings could not be translated

Some strings in Settings - Messages and Email Options could not be translated because t-functions not used for output.
To correct this just change the following function (add t-function for #title generation):

/**
 * Helper function to build the settings form for the notification messages
 */
function _user_relationships_message_settings_form(&$form, $defaults = array()) {
  foreach ($defaults as $key => $value) {
    if (is_array($value)) {
      $form[$key] = array(
        '#type'         => 'fieldset',
        '#title'        => t(ucfirst(str_replace('_',' ',$key))),
        '#collapsible'  => TRUE,
        '#collapsed'    => TRUE
      );
      _user_relationships_message_settings_form($form[$key], $value);
    }
    else {
      $form["user_relationships_msg_{$key}"] = array(
        '#type'           => 'textfield',
        '#title'          => t(ucfirst(str_replace('_',' ',$key))),
        '#default_value'  => variable_get("user_relationships_msg_{$key}", $value)
      );
    }
  }
}