title: ambiguous column name: error not working with tags
body: <p>I have some code to display my recipes in order of their popularity  as shown below. This is stored in my index file for the recipe view.</p>
  
  <pre><code>&lt;% @all_recipes.this_week.reorder("likes_count DESC").limit(10).each do |i| %&gt;
    &lt;%=link_to image_tag(i.image(:fixed), alt: "MUC", :class =&gt; "browse-recipes"), i %&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>As you can see I have passed a method 'this_week' which works perfectly defined as a scope. </p>
  
  <p>My issue is, I have a tag cloud on the same page and when I click on a tag is should refresh the page but showing only those recipes with the associated tag.This works perfectly WITHOUT the this_week method applied but if the method is there I get the following error:</p>
  
  <pre><code>SQLite3::SQLException: ambiguous column name: created_at: SELECT  "recipes".* FROM     "recipes" JOIN taggings recipes_taggings_81e277c  ON recipes_taggings_81e277c.taggable_id = recipes.id AND recipes_taggings_81e277c.taggable_type = 'Recipe' AND recipes_taggings_81e277c.tag_id = 33 WHERE "recipes"."live" = 't' AND (created_at &gt; '2014-01-13 00:00:00.000000')  ORDER BY likes_count DESC LIMIT 10
  </code></pre>
  
  <p>Any thoughts? Much appreciated.</p>