title: IQueryable.OrderBy() raises ArgumentNullException
body: <p>I'm querying a database view with LINQ and EF, and putting in the OrderBy() method causes the following exception to come up when ToList() is called on it:</p>
  
  <pre><code>Value cannot be null.
  Parameter name: input
  </code></pre>
  
  <p>None of my parameters are null, and the sort field is a non-nullable field (I checked the DB, and no null entries have sneaked in).</p>
  
  <p>Any ideas? If it helps, I'm calling it after querying, deduping (using GroupBy().FirstOrDefault()) and ToLiost()ing that.</p>