Description:
------------
There's some unexpected behavior to this function. According to documentation, the fourth parameter is optional. However, if you include the third parameter and omit the fourth, the function will error out with a warning. Either the documentation is wrong or this is a bug in 5.2. Given that it does 

This appears to be fixed as of 5.3.1 (tested on RHEL 6 beta)

Test script:
---------------
<?php
$ref = dns_get_record('php.net', DNS_A, $ns);
var_dump($ref);
?>

Expected result:
----------------
array(1) { [0]=>  array(5) { ["host"]=>  string(7) "php.net" ["type"]=>  string(1) "A" ["ip"]=>  string(13) "69.147.83.197" ["class"]=>  string(2) "IN" ["ttl"]=>  int(84264) } }

Actual result:
--------------
Warning: Wrong parameter count for dns_get_record()
NULL