I think I already answered you on some other thread, but anyway, I'll do it again:
take a look around in forums (use the search link) for a working iptables configuration.
If you are unable to find one, just ask again (I can tell, you, if you really search, you'll find it, I have, so you can ;-P ). I've very little time this week, so I can't search for it right now. sorry
Greetings.