Serialize not working as expected. Am I doing it wrong?

I reported the bug here:
http://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/647-serialize-d-array-not-unserializing-properly

But the replies are to the tone of "it's not a bug". Serialize isn't
working how I expect it to, but I was wondering if I'm just looking at
it all wrong.

The code I'm using is essentially what you see in the bug report.

Thanks.