My DNS server (bind 9) was writing on the syslog quite often the common error message:
[b]lame server resolving[/b].

A server is marked as lame when either an NS record points to an
incorrect host, or the authoritative server is not giving authoritative
anwers (that means is responding from his cache).

Solution:

You can turn off the logging by adding the following in your /etc/named.conf.

logging {
category lame-servers { null; };
};