I've recently upgraded from Ruby 1.8.6 and Rails 2.3.4 to Ruby 1.9 and Rails 3.0.3.

I have the following controller:

class ChartController < ApplicationController

  before_filter :login_required

  respond_to :html, :xml  

  def load_progress  

    chart.add( :series, "Memorized",  y_memorized )
    chart.add( :series, "Learning",   y_learning  )
    chart.add( :series, "Mins / Day", y_time      )  
    chart.add( :user_data, :secondary_y_interval, time_axis_interval )

    respond_to do |fmt|
      fmt.xml { render :xml => chart.to_xml }
    end

    # Also tried
    # respond_with chart

  end   
end

However, when I call the 'load_progress method' I get the following:

Started GET "/load_progress.xml" for 127.0.0. Processing by ChartController#load_progress as HTML Completed 406 Not Acceptable in 251ms

I have also tried changing the respond_to block to

respond_with chart

But I get the same response. I've read all the new Rails documentation on the new respond_with format but I can't seem to elicit an XML response. Am desperately hoping someone has some ideas.