Rails 3 rendering XML problem

I have Rails 3 application (running Rails RC1), and I have the following

class PluginsController < ApplicationController
  respond_to :html, :xml, :json

  def index
    @plugins = Plugin.all
If I try to render http://localhost:3000/plugins it works fine, showing
me the HTML version. If I try to get http://localhost:3000/plugins.json,
it also correctly sends me the JSON response.

However if I try http://localhost:3000/plugins.xml, I get the following

Template is missing

Missing template plugins/index with {:locale=>[:en, :en],
:handlers=>[:rjs, :haml, :erb, :rhtml, :builder, :rxml]} in view paths
Also, my ApplicationController is pretty simple:

class ApplicationController < ActionController::Base
  layout 'application'
I have tried taking out the layout line from the control, but same

Don't know if it's relevant, but I am using HAML and I only have one
view file called plugins/index.haml.html.

Any ideas why this may be happening?