Okay. when I looked at your IPTABLES config, I thought everything looked fine. I did a quick search, however, and noticed a couple of discrepencies that might be affecting your networking question:
Port Forwarding using Iptables
Since I have been using 2.4 kernel, I use iptables for firewall and NAT. So these are the Iptable rules required for port forwarding xxx.xxx.xxx.xxx:8888 to 192.168.0.2:80 .
/sbin/iptables -t nat -A PREROUTING -p tcp -i eth0 -d xxx.xxx.xxx.xxx
--dport 8888 -j DNAT --to 192.168.0.2:80
/sbin/iptables -A FORWARD -p tcp -i eth0 -d 192.168.0.2 --dport 80 -j ACCEPT
This was taken from http://www.hackorama.com/network/portfwd.shtml
These are commands that can be issued directly from the commandline. You might need to specify which eth card the rule applies to. The xxx.xxx.xxx.xxx is the WAN side, by the way.
Hope this helps in some way. If I'm a little off, I'm sure someone will come along and correct me.