After tweaking around a bit, I found that auto-completion would start to work if I changed the URL in the get line of file authsubs_controller.rb (action listdocs) to use HTTPS instead of HTTP:
feed = client.get('https://docs.google.com/feeds/documents/private/full?title=' + URI.escape(params[:q])).to_xml
Am I missing something?
I have the same problem. I tried your solution, but not solve the bug...