IP - 199.120.225.4 list.dsbl.org: - DNS not responding correctly

HI,

We noticed that list.dsbl.org is not resolving.  However, 
lists.dsbl.org is resolving.

 > list.dsbl.org
Server:  maxwell.gta.com
Address:  192.168.71.254

*** No address (A) records available for list.dsbl.org
 > lists.dsbl.org
Server:  maxwell.gta.com
Address:  192.168.71.254

Non-authoritative answer:
Name:    lists.dsbl.org
Address:  205.231.29.240


 From your usage page we should use list.dsbl.org.

Is there a DNS problem?  Or has the name changed.

Regards,

David Brooks
GTA Technical Support Manager
www.gta.com