I don't know if anyone else going through the book has had this problem, hopefully someone can help me out!

I've just run
Code:
rake test:units
(as on pg 242) after adding the tests to test a vote's relationship to a story and the voting history order, and rather than all the tests passing, like in the screenshot, I've got 3 failures!

I don't think I'm good enough to understand the errors I got given. Can anybody please help me?!

Code:
Macintosh-9:shovell Laura$ rake test:units
(in /Users/Laura/shovell)
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -Ilib:test "/Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake/rake_test_loader.rb" "test/unit/story_test.rb" "test/unit/vote_test.rb" 
Loaded suite /Library/Ruby/Gems/1.8/gems/rake-0.8.1/lib/rake/rake_test_loader
Started
..F..FF
Finished in 0.127123 seconds.

  1) Failure:
test_should_have_a_votes_association(StoryTest)
    [./test/unit/story_test.rb:23:in `test_should_have_a_votes_association'
     /Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/testing/setup_and_teardown.rb:33:in `__send__'
     /Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/testing/setup_and_teardown.rb:33:in `run']:
<[#<Vote id: 953125641, story_id: 1, created_at: "2008-07-11 13:25:45", updated_at: "2008-07-11 13:25:45">,
 #<Vote id: 996332877, story_id: 1, created_at: "2008-07-11 13:25:45", updated_at: "2008-07-11 13:25:45">]> expected but was
<[]>.

  2) Failure:
test_should_return_highest_vote_id_first(StoryTest)
    [./test/unit/story_test.rb:27:in `test_should_return_highest_vote_id_first'
     /Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/testing/setup_and_teardown.rb:33:in `__send__'
     /Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/testing/setup_and_teardown.rb:33:in `run']:
<#<Vote id: 996332877, story_id: 1, created_at: "2008-07-11 13:25:45", updated_at: "2008-07-11 13:25:45">> expected but was
<nil>.

  3) Failure:
test_story_association(VoteTest)
    [./test/unit/vote_test.rb:5:in `test_story_association'
     /Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/testing/setup_and_teardown.rb:33:in `__send__'
     /Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/testing/setup_and_teardown.rb:33:in `run']:
<#<Story id: 953125641, name: "My shiny weblog", link: "http://poocs.net/", created_at: "2008-07-11 13:25:45", updated_at: "2008-07-11 13:25:45">> expected but was
<nil>.

7 tests, 7 assertions, 3 failures, 0 errors
rake aborted!
Command failed with status (1): [/System/Library/Frameworks/Ruby.framework/...]