title: HibernateException: Found two representations of same collection
body: <p>If I save an object containing the following list</p>
  
  <pre><code>@OneToMany(cascade=CascadeType.ALL, mappedBy="taskList")
  @OrderColumn(name="position", nullable=false)
  public List&lt;Task&gt; tasks = new ArrayList&lt;Task&gt;();
  </code></pre>
  
  <p>I get the exception</p>
  
  <pre><code>org.hibernate.HibernateException: Found two representations of same collection
  </code></pre>
  
  <p>The code in the Play! controller looks like this:</p>
  
  <pre><code>TaskList taskList = taskList.findById(taskListId);
  taskList.add(position, task);
  taskList.save();
  </code></pre>
  
  <p>If I insert <code>taskList.refresh()</code> before this block it works, but the position information is lost (which leads to other errors).</p>
  
  <p>Is this a Hibernate bug or is something wrong with my code?</p>