namespace method is not 'symbolizing' composite names when rendering xml

In a tokamak file, when passing an object, which the class has a composite name, to namespace method, it should render the namespace name separated with underscore (_), but nowadays it's just appending the names.

Summary example

tokamak:

  namespace(@content_collection, domain_content_collections_url, :eager_load => false) {}

 <feed xmlns="http://www.w3.org/2005/Atom" xmlns:contentcollections="http://local.cms.abril.com.br:3000/content_collections">

  <feed xmlns="http://www.w3.org/2005/Atom" xmlns:content_collections="http://local.cms.abril.com.br:3000/content_collections">

Full example

show.tokamak
describe_collection(@content_collection.content_references) do |collection|

collection.id = domain_content_collection_url(@content_collection.id)
collection.title = @content_collection.title
collection.namespace(@content_collection, domain_content_collections_url, :eager_load => false) do |content_collection|
  content_collection.author = @content_collection.author
  content_collection.status = @content_collection.status
  content_collection.tags = @content_collection.tags
end
collection.describe_members do |member, content_reference|
  member.id = content_reference.resource_id
  member.links << link( :rel => :self, :href => member.id )
end

end

ATOM
<?xml version="1.0" encoding="UTF-8"?>

<id>http://local.cms.abril.com.br:3000/content_collections/4bd5a61063bb010e71000001</id>
<title>Título do conteúdo</title>
<updated>2010-04-26T16:54:07-03:00</updated>
<entry>
  <title>Título do conteúdo</title>
  <id>http://local.cms.abril.com.br:3000/articles/titulo-do-conteudo</id>
  <link href="http://local.cms.abril.com.br:3000/articles/titulo-do-conteudo" rel="self"/>
</entry>
<contentcollections:status>scratch</content_collections:status>
<contentcollections:tag>teste</content_collections:tag>
<contentcollections:tag>teste2</content_collections:tag>
<contentcollections:author>Manzan e Fer</content_collections:author>