Did you contact the site hosting the torrent/magnet files?

The same magnet links opens Transmission when I use in different browser like Chrome (again for Ubuntu).

It the magnet protocol registered properly in Linux?

• http://kb.mozillazine.org/Register_protocol
• network.protocol-handler.expose.<protocol> = false (not be opened in Firefox)
• network.protocol-handler.external.<protocol> = true (allow external app)

I tried this one too. However the dialog box opens for me to select the program to open the file with. However no apps/programs are shown in the list and I am not able to search for Transmission either.

So what is the site link?