Couldn't find constant LIBXML_VERSION

PHP Version 5.0.4

Error is this.

The feed was setup correctly and druing a cron run I got the following.

Warning: constant() [function.constant]: Couldn't find constant LIBXML_VERSION in /home/nashvillesnews/public_html/modules/aggregation/aggregation.module on line 1021

It is referencing this code in your module

function aggregation_get_XML($string, $feed = NULL)
{
// PHP versions earlier than 5.1 have different argument counts for simplexml_load_string,
// this condition was added to check against this case

if ((constant(‘LIBXML_VERSION’) === NULL) || (version_compare(phpversion(), ‘5.1.0’, ’<’))) 

LINE 1021

@ $xml = simplexml_load_string($string, NULL);
else
@ $xml = simplexml_load_string($string, NULL, LIBXML_NOERROR | LIBXML_NOWARNING);

// We got a malformed XML
if ($xml === FALSE)
{
$fragment = ’’;

if (!is_null($feed))
$fragment = ” while processing feed \”$feed->title\””;

throw new Exception(“XML malformed$fragment”, MALFORMED_XML);
}

return $xml;
}

The way I read this is that it is not going to take it unitll the php version is 5.1 or better. Maybe I'm not tracking this in my head correctly. Thanks