Are you with Mweb by any chance? I know Mweb has a setting where they'll block most of the unwanted inbound connection, which you can disable on your profile from their webpage.
Also, do you want to host a news server from your ADSL, or do you want to connect to a news server on that port?
The router might have to be rebooted for the Port Forwarding to take effect, but I actually doubt that it would be necessary.
You can actually verify it by logging in on the router with telnet client and then running 'iptables -t nat -L -v -n', and then there should be an entry for the port forward.
If you want to host a news server from your PC, then you need to make sure that you don't have any other firewalls blocking it. Secondly, you need to have the news server listen on 0.0.0.0 IP address, and not just on your LAN address.
You can run 'netstat -na' from within Command Prompt to make sure that your news server is indeed listening on TCP Port 0.0.0.0:563.
If you don't like using command line utilities, then you can download TCP View from Microsoft to get the same information and more
And lastly, the PC (which is going to run the news server) has to have its default gateway set to the router, which would be the default if you just kept it's IP address settings on
Obtain an IP address automatically.
It might seem silly that I mention this, but I've had it quite a few times where the PC could "see" the ADSL modem, since it's on the same IP range as the ADSL modem, but then the port forwarding wouldn't work because the default gateway wasn't set (which would mean that the PC never had Internet access).