non-authoritative answer from master

[Jim Reid]

>>>>> "John" == John Beamon <jbeamon at franklinamerican.com> writes:

    John> What could make a server say it's no longer
    John> authoritative for ANY of its zones?

[1] Syntax errors in the zone file, especially when (broken) shell
scripts are used to generate the zone files. Or if the zone files
share a common metafile that has a syntax error. Or if they are
derived from such a file.

[2] Syntax errors in  named.conf.

[3] The name server is using a different config file from the one you
think it's using.

For [1] and [2], consult the name server's logs. named-checkzone and
named-checkconf are your friends for [1] and [2] respectively. For
[3], check the scripts and boot-time stuff used to start the name
server.