rails trying to load prototype in production

I'm using jQuery and I have this line in my Application.rb:

    config.action_view.javascript_expansions[:defaults] = %w(jquery
rails application)

Everything works fine in development, but in production I notice that
Rails is trying to load all the prototype files and there's nothing in
the production environment file that's telling it to do that. Why is
it trying to load prototype?

If you look at the html (View > Page Source or similar in your
browser) what do you see (presumably in the head) for loading
javascript. Check it in development and then production mode.

Colin