collection_select option ":selected" not working

The ":selected" statement is not working. Ideas why? Similar experiences?

<%= start_form_tag :action => 'dummy' %>
<% @teams = Team.find(:all) %>
<label for="team_id">Team</label><br/>
<%= collection_select("team", "id", @teams, :id, :name, {
:include_blank => true, :selected => @teams[5].id }) %>
<%= end_form_tag %>

It is generating the follwing code:

<form action="/games/dummy" method="post">
<label for="team_id">Team</label><br/>
<select id="team_id" name="team[id]"><option value=""></option>
<option value="1">Baltimore</option>
<option value="2">Buffalo</option>
<option value="3">Cincinnati</option>
<option value="4">Cleveland</option>
<option value="5">Denver</option>
<option value="6">Houston</option>
<option value="7">Indianapolis</option>
<option value="8">Jacksonville</option>
<option value="9">Kansas City</option>

... etc



Oddly, the option :for include_blank is working, while the selected
right next to it is not.

Please help.

Try this:

<%= collection_select("team", "id", @teams, :id, :name,
{:include_blank => true}, {:selected => @teams[5].id }) %>

I think :selected belongs in html_options instead of options:
collection_select(object, method, collection, value_method,
text_method, options = {}, html_options = {})