acts_as_tree undefined method?

i have acts_as_tree installed as plugin under rails 2.0.2 and also its defined in class TreeItems, but when i put this in my view

  <ul class="tree_level1" id="cars">Furniture     <% TreeItem.root.category.children do |cat_children| %>       <li><a class="list_item" href="#"><%=h cat_children.name %></a></

    <% end %>   </ul>

it gives me this:

undefined method `acts_as_tree' for #<Class:0x2bb3f30>

fixed it, restarted webrick server :smiley: