Hi AngusMac,
Yes, I would restart the computer to see if it worked properly.
There is one more thing we can try. I checked into it and you can also disable the Smart Install from the EWS.
Setup the printer by Ethernet connection.
Print off a configuration page to get the printer's IP address.
Then type the IP address in a web browser to bring up the printer's Embedded Web Server and you should be able to disable the Smart Install through here.
Let me know how you made out.
Thank You.