DDNS error emails from System Admin module

I recently took advantage of the offer for the System Admin module if you update to the latest version when you register. The one feature there that looks interesting is the DDNS setup however it does not appear to be working. Enabling it seems to go OK and it retrieves the right external IP address. However it appears to fail to update the remote DNS and the scheduled check just sends me an email with a failure.

This is all running on CentOS 6.6. The emails that I receive hourly are as shown below. As you might imagine I have tried to turn the new feature off (Disabled) but it appears to auto-enable. Is there a way either to get it working (preferred) or disable this feature?

Thanks, M

Subject:
Cron < asterisk@xxxxxxxx > /var/lib/asterisk/agi-bin/ddns_client.php

Content:
PHP Fatal error: Uncaught exception 'Pest_ServerError' in /var/www/html/admin/libraries/pest/Pest.php:308
Stack trace:
#0 /var/www/html/admin/libraries/pest/Pest.php(242): Pest->checkLastResponseForError()
#1 /var/www/html/admin/libraries/pest/Pest.php(364): Pest->doRequest(Resource id #96)
#2 /var/www/html/admin/modules/sysadmin/Reg.class.php(24): Pest->post('/deployment/dns', Array)
#3 /var/www/html/admin/modules/sysadmin/Sysadmin.class.php(823): FreePBX\modules\Sysadmin\Reg- >kPost('/deployment/dns', Array)
#4 /var/lib/asterisk/agi-bin/ddns_client.php(15): Sysadmin->sendDDNSUpdate()
#5

thrown in /var/www/html/admin/libraries/pest/Pest.php on line 308

Originally reported in the FreePBX forum and I was asked to report it here.
http://community.freepbx.org/t/ddns-error-emails-from-system-admin-module-feature/28396