cache only..urgent!

[omphile]

I've been trying to configure a cache only server. My configuration
appears below. according to DNS & BIND that should be enough. i tried
nslookup, and the host/domain unknown response showed. what could i
poosibly have left out?  syslog has no complaints. Please help!   : )
:)

//---  /etc/namedb/db.127.0.0

@ IN   SOA  limpopo.ub.bw.  root.savuti.ub.bw.   (
    2000110100   ;Serial
    10800      ; refresh
    3600       ; retry
    604800     ; expire
    86400 )    ; minimum TTL


               IN     NS   limpopo.ub.bw.


1            IN     PTR   localhost.

==========/etc/named.conf===========

options {
 directory "/etc/namedb";
};

zone "0.0.127.in-addr.arpa" in {
    type master;
    file "db.127.0.0";
};

zone "." in {
    type hint;
    file "db.root";
};
============================


/etc/namedb/db.root
......................