CodeRay and RedCloth in a Rails 3 application

Question

I'm trying to add CodeRay and RedCloth to a Rails 3 application and am getting some strange behaviors. I followed this RailsCast, but since Rails 3 escapes the HTML by default, my HTML is being escaped a couple of times. What do I need to change?

module ApplicationHelper
  def coderay(text)
    text.gsub(/\<code( lang="(.+?)")?\>(.+?)\<\/code\>/m) do
      content_tag("notextile", CodeRay.scan($3, $2).div(:css => :class))
    end
  end
end

<%= textilize(coderay(@post.body)) %>