Hi.
I've encountered a strange bug when trying to sort DOM items by specific params.
My code looks like this:

$manager = new DataObjectManager(
 $this,
 'MyObjects',
 'MyObject',
 array(
  'Title' => 'Title',
  'Date' => 'Date',
 ), 
 'getCMSFields_forPopup',
 '',
 'Title DESC, ID DESC'
);
$fields->addFieldToTab('Root.Content.MyObjects', $manager);

The manager works just fine, but when I try to open a pop-up, an SQL error occurs.
I noticed that the problem is with the sorting params, the SQL statement for the popup contains a following piece of code:

ORDER BY Title DESC, ID DESC ASC LIMIT 10

Notice that the 'ASC' param is added unnecessarely.
How do I fix that?