port forwarding

I'm having some problems configuring coyote linux to do NAT. I've been running
a web server on Mandrake 8.1 and also had that same machine using iptables to
share a connection with a Win2k computer.

Now, I set up coyote linux to run off a 3rd computer and want my linux web
server and Win2k boxes behind it. Everything seems to be working fine except
accessing the web server. From both computers, I can access my web page by
entering http://192.168.0.5 (linux IP). But, when I type in my external IP
given box cox, I am unable to get it to forward port 80 to the 192.168.0.5
computer.

I've been following directions on
http://www.dalantech.com/coyote-faq.shtml#portforward

I added this line to my rc.firewall

/sbin/ipmasqadm portfw -a -P tcp -L x.x.x.x 80 -R 192.168.0.5 80
x being the IP assigned by dhcp/cox.

I also tried this and it didn't seem to work either.
/sbin/ipmasqadm autofw -A -r tcp 80 80 -h 192.168.0.5

Can someone help me out in what I'm doing wrong?

Thanks,
Virgil