I've gone through the instructions here to configure Deluge, and I've also gone through these instructions to set up the necessary scripts.
The username I chose for DELUGED_USER was the user name I was logged in with, i.e. the Unity desktop user.
I executed each of the commands as instructed and received no error messages. Upon restart, deluged was not running. When I executed sudo update-rc.d deluge-daemon defaults I got a warning that the entry already exists. Manually executing sudo invoke-rc.d deluge-daemon start works, and I am able to connect.
It appears as though the start-up script will not execute at start-up, however there doesn't appear to be anything wrong with the script as executing it manually successfully starts the daemon.
Any idea why this might be happening?