title: Why are checkmarks not being displayed when UITableView.allowsMultipleSelection is enabled?
body: <p>I have a UITableView in an iOS5.1 app where I set</p>
  
  <pre><code>self.tableView.allowsMultipleSelection=YES;
  </code></pre>
  
  <p>The Apple documentation states "When the value of this property is YES, a check mark is placed next to each row that is tapped. Tapping the row again removes the check mark.".</p>
  
  <p>I am able to select multiple rows as the background is set to Blue. However, no checkmarks are displayed. Does the checkmark need to be set as shown below in didSelectRowAtIndexPath because I am using custom UITableViewCells? </p>
  
  <pre><code>cell.accessoryType = UITableViewCellAccessoryCheckmark;
  </code></pre>