DNS help needed

[Shane]

Hi List,

I've got an annoying DNS problem at the moment where we've found 2
addresses that fail to resolve in one of our offices that resolve fine
in the other ...

We have a master DNS server that has all the info for our hosts, the
other office DNS servers slaves our zone. Both have a *.* zone defined
to use named.root (I'll paste the two config files below as they'll
probably help).

the named.root files are identical on the two servers - the slave is
the one resolving correctly. The two addresses we know of failing so
far are:
bigpond.net.au
3delight.com
so it shouldn't be anything to do with our zone info, seems to be
something between "us" and "them" but I'm stuck for ideas on where
and/or how to fix the problem. We tried using forwarders for a while
but that led to a whole lot of other problems so I'd rather stick to
getting the root zone working properly :-)

TIA,
Shane.

"Master config"
options {
        directory "/var/named/";
        allow-transfer{
                10.0.0.0/8;
        };
        listen-on {
                10.5.0.10;
                127.0.0.1;
        };
        query-source address * port 53;
};

logging{
        category lame-servers{
                null;
        };
        category security{
                default_syslog;
        };
        channel update_debug {
                file "/var/log/update-debug.log";
                severity  debug 3;
                print-category yes;
                print-severity yes;
                print-time     yes;
        };
        category update { update_debug; };
};

zone "." {
        type hint;
        file "named.root";
};

zone "rsp.com.au"{
        type master;
        file "rsp.hosts";
        also-notify{
                10.2.0.10;
        };
};

zone "10.IN-ADDR.ARPA"{
        type master;
        file "10.rev";
        also-notify{
                10.2.0.10;
        };
};

zone "168.192.IN-ADDR.ARPA"{
        type master;
        file "192.168.rev";
        also-notify{
                10.2.0.10;
        };
};

zone "0.0.127.IN-ADDR.ARPA"{
        type master;
        file "localhost.rev";
};


SLAVE config:
options {
        directory "/var/named";
        listen-on {
                10.2.0.10;
        };
};

controls {
        inet 127.0.0.1 allow { localhost; } keys { rndckey; };
};
zone "." IN {
        type hint;
        file "named.root";
};


zone "0.0.127.in-addr.arpa" IN {
        type master;
        file "localhost.zone";
};

zone "rsp.com.au" IN {
        type slave;
        file "rsp.hosts";
        masters { 10.5.0.10; };
};

zone "10.in-addr.arpa" IN {
        type slave;
        file "10.rev";
        masters { 10.5.0.10; };
};

zone "168.192.in-addr.arpa" IN {
        type slave;
        file "192.168.rev";
        masters { 10.5.0.10; };
};

include "/etc/rndc.key";