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 > 

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