authlogic's password field is not required in rspec?

Hello,

I am using authlogic and rspec in our project. I steup the authlogic as the offical example. But when i run my rspec, it tells me that password field is not required. My spec file is as following:

require 'spec_helper'

describe User do   before(:each) do     @valid_attributes = {       :email => 'tcsnhj@gmail.com',       :password => "aaaaaa",       :password_confirmation => "aaaaaa"     }     @user = User.new(@valid_attributes)   end

......

  it "should not be valid without a password" do     @user.password = nil     @user.should_not be_valid   end ........ end

the rspec show me "expected valid? to return false, got true". but when I run the application in firefox, and if I leave the password field empty, the form will give errors. I also run irb: @user = User.new( :email => "gaga@gag.com", :password = nil, :password_confirmation = 'a' * 10), the @user.valid? returned false.

Why the rspec got true? .

Anyboby know why? I am waiting online!