title: Error: Cannot apply $push modifier to non-array in Meteorjs
body: <p>This is a function to add a dictionary as a subitem of a main document.</p>
  
  <pre><code>addSubItem = function(id, data) {
    s = Item.findOne(id);
    if(s){
      Item.update({_id:id},{$push:{'subItemsList':data}});
    }
  };
  </code></pre>
  
  <p>I verify the data passed and are a valid main document id a subitem data.</p>
  
  <pre><code>data = {num:1, value: 'Subitem1'};
  </code></pre>
  
  <p>This works fine yesterday with the latest version of meteor (0.4.2), but today I get this message at javascript console:</p>
  
  <pre><code>Error: Cannot apply $push modifier to non-array
  </code></pre>
  
  <p>I created and setup a new project and I still get the same.</p>