Issues in Devise plugin. (Rails)

I have set up all things that the Devise needs. And things works fine for me.

But there is one thing very annoying:

When I request the pages which need authentication through the browser(Firefox).It just pop out an alert dialog says:

"A username and password are being requested by http://localhost:3001. The site says: "Application"'  

with the user name and password input fields instead of redirecting to the login page (the "/users/sign_in" page).But even, whatever user name and password I typed in, I just can't access (I can successfully login through the "/users/sign_in" with the same info).

Help please :(

Update with my model:

class Account < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable, :lockable and :timeoutable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation, :remember_me
end

My controller (generated from the scaffold):

class ThingsController < ApplicationController
  before_filter :authenticate_account!, :except => ['show', 'index']
  # GET /things
  # GET /things.xml
  def index
    @things = Thing.all

    respond_to do |format|
      format.html # index.html.erb
      format.xml  { render :xml => @things }
    end
  end

  # GET /things/1
  # GET /things/1.xml
  def show
    @thing = Thing.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.xml  { render :xml => @thing }
    end
  end

  # GET /things/new
  # GET /things/new.xml
  def new
    @thing = Thing.new
....

if you need more information, please 开发者_Go百科let me know :)

I had this issue a few weeks ago. I forget where I found this solution, but adding the following line to my devise initializer took care of the problem for me.

# config/initializers/devise.rb
config.navigational_formats = [:"*/*", :html]