Hi,

please modify the contact.inc.php file and add the missing function call: setReceiptTimestamp();.

  // check form session and time used to complete the form:
  setReceiptTimestamp(); // Missing function call!
  // if (empty($_SESSION[$settings['session_prefix'].'user_id'])) {
  if (!isset($_SESSION[$settings['session_prefix'] . 'receipt_timestamp_difference']) || intval($_SESSION[$settings['session_prefix'] . 'receipt_timestamp_difference']) <= 0)
   $errors[] = 'error_invalid_form';
  else {
   if ($_SESSION[$settings['session_prefix'] . 'receipt_timestamp_difference'] < $settings['min_email_time'])
    $errors[] = 'error_form_sent_too_fast';
   elseif ($_SESSION[$settings['session_prefix'] . 'receipt_timestamp_difference'] > $settings['max_email_time'])
    $errors[] = 'error_form_sent_too_slow';
  }

This, hopefully, solves the problem.

regards
Micha