Router Settings - D-Link DSL-504

[phrozen1]

Ok... Heres the situation.
I am trying to run a web server from this machine, using Abyss.

My ISP is not blocking any ports - no problems there.
I've narrowed down the possible causes.
The router is my problem - there are several functions that I have a problem with.

Even a direct link to my IP address comes up with 'Connection Refused', so I think my router blocks all incoming server requests... The web server works on the internal network.

I'm using a D-Link ADSL Modem Router (Model DSL-504).
Functions that I would appreciate someone explaining to me are:
(Please include whether they should be on or off, any additional notes etc.)

NAT
DMZ
DHCP

Port forwarding is all in order.
My server address is http://203.12.160.35:8000/
Web server is running on port 8000, the router redirects port 8000 to this PC.
The problem is getting the router to respond to requests - not sure what the problem is there...

Ok, my router settings are as follows (so you have a better idea about the setup):
Internal Router IP: 192.168.0.1
DHCP Client: Off
NAT: Enabled
IPSec: On
PPTP: On
DMZ: Disabled

Port Redirection Settings:
State: Enabled
Protocol: TCP
Port: 8000 Redirected
Local IP to forward port to: 192.168.0.4

Any suggestions or settings information would be good.

Perhaps someone could leave detailed instructions that tell me what to turn on and off in the router's settings?