Pasting a URL into Transmission

[Hairy]

Hi all,
Long time since my last post as everything has been great since I set everything up. ReadyNAS Duo with WebSVN and Transmission installed.
However, Ive just changed broadband providers and Im setting up my router. Ive just external access to Transmission through the firewall, I can add torrents in the upload dialog my downloading the file locally first and selecting the file to upload, but pasting the url to the public torrent and clicking Upload, nothing happens. The torrent isn't added.
Im guessing its something I will need to configure on my router, I probably set it up on my original router, but I cant seem to work it out.

Any help would be appreciated!

Thanks
John

[Hairy]

Still stuck on this, any suggestions at all?