I ran Shields up and that showed port 21 to be open and I've double checked the router has port forwarding enabled to this computer on port 21. I've also set filezilla client to passive mode but it still says unable to connect!
Although an article on no-ip.com I just read said that some routers won't allow access to a server held on a home networked PC from that or any other PC on the network via an external IP! So maybe I'll have to wait until tomorrow to test it from my grandparents PC!
