Seeing Machines behind a firewall

[Witness]

First of all here is my setup:

I have a server running Samba, with a WINS server, that acts a firewall.
I have recently upgraded it to Kernel 2.4.2 with NetFilter.  It is also
set up to forward ports 137,138,139 using both TCP and UDP protocols
using the following command:

iptables -t nat -A PREROUTING -i eth1 -p TCP -m multiport --port
137,138,139 -j DNAT --to 192.168.2.2
iptables -t nat -A PREROUTING -i eth1 -p UDP -m multiport --port
137,138,139 -j DNAT --to 192.168.2.2

Note: 192.168.2.2 is the WinME box; eth1 is the connection to the public
network.

Behind the firewall I have WinME machine that uses the WINS server on
the firewall.

On the outside of the firewall is a large public network that I want to
browse using the WinME machine.

I can browse the external network using smbclient -L [computername], but
I still cannot see it from my WinME box.  Is this just a matter of
disabling the WINS server? Or is there something else I need to do?  I
would like to keep the WINS server if possible, and if possible get it
to record the stuff from the external network.

Any ideas?

Thanks,

Ben Meyer
Witness