Jim, I must apologise, looking through all of my named config files I can't find one that has "@TTL" in it. I just mis-read something.
What I do have is a couple of files that don't have the $TTL declaration as the first line, but begin with the "@ A IN SOA..." line and no preceeding "$TTL".
The only problems I have are with some of the dynamic DNS addresses, and for some reason with all of the speedera.net addresses like www.nasa.gov, which always come back unknown.