Error in administration form submit function

File: ldapauth.admin.inc
Function: ldapauth_admin_settings_submit()
Part of function: Case structure

Error occured on sites with non-english localization.
In submit function case conditions never will be passed for translated title of buttons.

function ldapauth_admin_settings_submit($form, &$form_state) {
  $op = $form_state['clicked_button']['#value'];
  switch ($op) {
    case "Save configuration":
      $values = $form_state['values'];

      variable_set('ldapauth_login_process', $values['ldapauth_login_process']);
      variable_set('ldapauth_login_conflict', $values['ldapauth_login_conflict']);
      variable_set('ldapauth_forget_passwords', $values['ldapauth_forget_passwords']);
      variable_set('ldapauth_disable_pass_change', $values['ldapauth_disable_pass_change']);
      variable_set('ldapauth_alter_email_field', $values['ldapauth_alter_email_field']);

      drupal_set_message(t('The configuration options have been saved.'));
      break;
    case "Reset to defaults":
      variable_del('ldapauth_login_process');
      variable_del('ldapauth_login_conflict');
      variable_del('ldapauth_forget_passwords');
      variable_del('ldapauth_disable_pass_change');
      variable_del('ldapauth_alter_email_field');

      drupal_set_message(t('The configuration options have been reset to their default values.'));
      break;
  }

  // Rebuild the menu router.
  menu_rebuild();
}

Just change line:
case "Save configuration":
on
case t("Save configuration"):

AND

case "Reset to defaults":
on
case t("Reset to defaults"):