HTTP Port forwarding issues

[Big Daddy]

all,      for some reason i can get my smtp and pop3 to route from the  internet, but i cannot get http requests to forward correctly.  iptables -A FORWARD -p tcp -i eth0 -d $int_ip -p tcp --dport http -m state --state NEW -j ACCEPT  iptables -A FORWARD -p tcp -i eth0 -d $int_ip -p tcp --dport smtp -m state --state NEW -j ACCEPT (works)  iptables -A FORWARD -p tcp -i eth0 -d $int_ip -p tcp --dport pop3 -m state --state NEW -j ACCEPT (works)  iptables -t nat -A PREROUTING -d $ext_ip -p tcp --dport smtp -j DNAT --to-destination $int_smtp:25 (works)  iptables -t nat -A PREROUTING -d $ext_ip -p tcp --dport pop3 -j DNAT --to-destination $int_pop3:110 (works)  iptables -t nat -A PREROUTING -d $ext_ip -p tcp --dport http -j DNAT --to-destination $int_http:80  web server is running IIS5. any help would be great! Big D@ddy