title: ChangeConflictException in Linq to Sql
body: <p>I receive "Row not found or changed exception". </p>
  
  <pre><code>System.Data.Linq.ChangeConflictException: Row not found or changed. at
  System.Data.Linq.ChangeProcessor.SubmitChanges(ConflictMode failureMode) at
  System.Data.Linq.DataContext.SubmitChanges(ConflictMode failureMode)
  at System.Data.Linq.DataContext.SubmitChanges()
  </code></pre>
  
  <p>How I to tell what column causes the exception?</p>
  
  <p>Thank you.</p>