Does this block ( includes/modules/shipping/zones.php l. 279)

Code:
      if (strstr(MODULE_SHIPPING_ZONES_SKIPPED, $dest_country)) {
        // don't show anything for this country
        $this->quotes = array();
      } else {
        if ($error == true) $this->quotes['error'] = MODULE_SHIPPING_ZONES_INVALID_ZONE;
      }
need to be wrapped in


Code:
      if (zen_not_null(MODULE_SHIPPING_ZONES_SKIPPED)) { 
...
      }
I'm seeing:
[26-Jan-2012 19:41:43] PHP Warning: strstr() [<a href='function.strstr'>function.strstr</a>]: Empty delimiter in /home/MYSITE/public_html/includes/modules/shipping/zones.php on line 279

PHP is 5.2.17, Zen 1.3.9h.