Multiple-query log flood in Rails 2.3

I'm using acts_as_category plugin to manage my categories logic. In almost every page of the site the categories and sub-categories tree is shown:

<div id="categories_">
  <% Category.roots.each do |category| %>
    <h3><%= 开发者_JS百科category.name %></h3>
    <div>
      <ul class="subcat">
      <% category.children.each do |subcategory| %>
        <li><%= link_to subcategory.name, "/category/#{subcategory.to_param}" %></li>
      <% end %>
      </ul>
    </div>
  <% end %>
</div>

It produces a lot of SQL queries shown in the log file, is there a way to fetch multiple rows in a single query?

EDIT:

I tried rewriting the roots scope in Category model with the same results:

named_scope :roots,
            :conditions => ["((hidden IS NULL OR hidden = 0) AND (parent_id IS NULL))"],
            :include => :children

EDIT:

It seems that the problem is with the plugin, and the author explained here (http://goo.gl/MwRSJ) why it can't be changed. Any other suggestion for managing my Categories?. I've used acts_as_tree but it seem a bit outdated. Thanks!.

What you're seeing is the N+1 query problem which is solved by eager loading associations.

<% Category.roots(:include => :children).each do |category| %>