One of my DNS servers is no longer responding authoritatively for any of my domains. ns18.hostony.net is acting non-authoritatively for tiffman.com (and my add-on domains). Also, both of my primary DNS servers (ns19 and ns18) are reporting my SOA to be '.' rather than ns19.hostony.net, my primary nameserver. Could these issues be looked at and fixed? Thanks.

I need to know all of your domain names to help you.
Please go to http://support.hostony.com and submit a ticket with your problem.
Also do not forget to list your domains please.