How does this validation fail in console but not in rspec?

gistfile1.txt

ivan:~/Development/ruby/IvanEnviromanRefinery [git:master+]  → bundle exec rspec ../refinerycms-link/
.............................F.

Failures:

  1) BlogPost bookmark links must have a link url if it is a link
     Failure/Error: Factory.build(:post,
       expected valid? to return false, got true
     # /Users/ivan/Development/ruby/refinerycms-link/spec/models/blog_post_spec.rb:197:in `block (3 levels) in <top (required)>'

Finished in 6.56 seconds
31 examples, 1 failure

Failed examples:

rspec /Users/ivan/Development/ruby/refinerycms-link/spec/models/blog_post_spec.rb:196 # BlogPost bookmark links must have a link url if it is a link
ivan:~/Development/ruby/IvanEnviromanRefinery [git:master+]  → rails console
Loading development environment (Rails 3.0.9)
ruby-1.9.2-p180 :001 > b = BlogPost.new
 => #<BlogPost id: nil, title: nil, body: nil, draft: nil, published_at: nil, created_at: nil, updated_at: nil, user_id: nil, cached_slug: nil, custom_url: nil, link_url: nil, is_link: nil, custom_teaser: nil> 
ruby-1.9.2-p180 :002 > b.title=' 2011-06-24 8:34 '
 => " 2011-06-24 8:34 " 
ruby-1.9.2-p180 :003 > b.body='goo'
 => "goo" 
ruby-1.9.2-p180 :004 > b.is_link = true
 => true 
ruby-1.9.2-p180 :005 > b.valid?
 => false
ruby-1.9.2-p180 :007 > b.save
 => false 
ruby-1.9.2-p180 :008 > b.errors
 => {:link_url=>["must have a link_url if is_link is true"]} 
ruby-1.9.2-p180 :009 > 

ok, so I also built the factory in console, and it's not a problem with factory_girl

ruby-1.9.2-p180 :017 > f =  Factory.build(:post,
ruby-1.9.2-p180 :018 >                         :title => "a link",
ruby-1.9.2-p180 :019 >                         :body => "link text",
ruby-1.9.2-p180 :020 >                         :is_link => true)
 => #<BlogPost id: nil, title: "a link", body: "link text", draft: false, published_at: "2011-06-24 16:52:09", created_at: nil, updated_at: nil, user_id: nil, cached_slug: nil, custom_url: nil, link_url: nil, is_link: true, custom_teaser: nil> 
ruby-1.9.2-p180 :021 > f
 => #<BlogPost id: nil, title: "a link", body: "link text", draft: false, published_at: "2011-06-24 16:52:09", created_at: nil, updated_at: nil, user_id: nil, cached_slug: nil, custom_url: nil, link_url: nil, is_link: true, custom_teaser: nil> 
ruby-1.9.2-p180 :022 > f.valid?
 => false 
ruby-1.9.2-p180 :023 > f.save
 => false 
ruby-1.9.2-p180 :024 > f.errors
 => {:link_url=>["must have a link_url if is_link is true"]} 
ruby-1.9.2-p180 :025 > 

blog_post_spec.rb

require 'spec_helper'
Dir[File.expand_path('../../../features/support/factories/*.rb', __FILE__)].each{|factory| require factory}

describe BlogPost do
  let(:blog_post ) { Factory :post }

  ...

    describe "bookmark links" do
    it "may have a bookmark link" do
      Factory.build(:post,
                    :title => "a link",
                    :body => "link text",
                    :is_link => true,
                    :link_url => "http://example.com").should be_valid
    end
    it "must have a link url if it is a link" do
      Factory.build(:post,
                    :title => "a link",
                    :body => "link text",
                    :is_link => true).should_not be_valid
    end     
  end

so, this all works fine if you use .should be_invalid

and now it's working the original way. perhaps re-starting spork did the trick? borked by spork