Robot causing MissingTemplate by sending :formats=>["text/*"], :locale=>[:en, :en]

Our production site occasionally gets the following error, which sends
everyone on the team an email:

Started GET "/" for at 2011-05-13 10:53:16 -0400
  Processing by HomeController#index as
ActionView::MissingTemplate (Missing template home/index with
{:handlers=>[:erb, :rjs, :builder, :rhtml, :rxml],
:formats=>["text/*"], :locale=>[:en, :en]} in view paths "etc...")

Of course, if you browse to that page it comes up fine. I have two questions:

1) How can I reproduce this? Is there some way I can request the page,
either through a browser or with curl or something else, that would
set the request headers in a way that would trigger this error?

2) How do I fix this? I've googled around and the suggestion seems to
be to create another view with ".en" in the file name. That seems
really wrong to me.

Thanks for any insight about what is going on. The server is CentOS,
with Apache and Passenger. The app is Rails 3 and has happened with a
few versions: 3.0.3, 3.0.5, and 3.0.7. The app is fairly old, but I
think I created a blank project in Rails 3.0 beta, then dragged all my
old code to the new project.

I've got the same problem. Maybe a before_filter method could solve
it? See:

But this seems to be limited to controllers who don't respont to
different formats.

"But this seems to be limited to controllers who don't respond to
different formats."

That sounds like a clue. These actions don't. I'll put this at the
bottom of the controllers and see if that helps:

respond_to do |format|