iptables port forwarding problem.

[Greg Fischer]

I've spent an embarrasingly long period of time trying to get this to
work. I'm trying to port forward port 6699 from 192.168.0.1 (my firewall
machine) to 192.168.0.112:6699 in order to allow others to access my
mp3s via napster.  Here is the relivant line, anyone know what I'm doing
wrong? 

/sbin/iptables -t nat -A PREROUTING -d 192.168.0.1 -p tcp --dport 6699
        -i eth0 -j DNAT --to-destination 192.168.0.12:6699

Where eth0 is my net connection.  Any ideas?

Thanks

--Greg