Hosting Doom 3 through a D-Link DSL-G604T

I have been trying all week to run a dedicated server through my
router, the D-Link DSL-G604T with no success.
When I use a Speedtouch modem it works fine but not through the router.

I run windows XP SP2 and have configured this to have a static IP.

I can join a game on the internet but I cannot host one.
I have tried the virtual server settings , when this didn't work I
enabled DMZ for my IP I even disabled the firewall on the router and
still no luck.

Has anyone been able to host games through this router ?
I should mention that I have the same problem with another game I
tried, Call Of Duty. This also works if I just use my old broadband
modem.