getting my own IP back

[julianop]

After setting up a bind 9 installation (before I go live and update my zone
info at my registrar),  nslookup and dig called from the DNS server return
my own fixed IP for every inquiry I make, when I specify my own IP for the
server. If I don't specify my own server on the comand line, and rely on my
ISP's DNS server, I get the correct result.

I'm running a single fixed IP, and have five machines on a private subnet,
and have port 53 punched through to the real world, NATed to the Linux box,
if that makes any difference.

Anyone know what I could have done wrong, please?