After a horrible experience and a week of swearing at a Linksys WRT54G (would only allow one wireless connection, and a very poor one at that), I took it back and swapped it for a Belkin F5D7230UK4 which works great... great, apart from one thing...
With the Linksys I could use my Remote connection (Both Windows Remote Desktop and VNC) no problem. The setup on the PC hasn't changed, so it isn't that, therefore it must be the Belkin router at fault.
There is no port forwarding with this router, only virtual servers, which apparently won't let me connect no matter what. The connections work ok as I can get them working ok over the LAN using IP addresses, but no way will they work using my dyndns hostname and a browser. I've even tried switching off the router's firewall (no XP firewall running), but still the same.
The one thing which doesn't look right to me is despite the PC having a static IP of 192.168.0.5 the router still shows it in the connected clients list as 192.168.0.100 - The DHCP on the router is set to assign addresses from 100 > 120. Idea's anyone, before this one goes back as well??