I just wanted to post this in the (odd) case that someone runs in the same problem I did.
I had a custom class extending page called "Processes" that could contain any number of children DataObjects "process".
When I would add "processes" to my menu and click on it, I would get a Blank Screen of Death.
But calling the "Process" objects from a custom function worked. And my "processes" class contained only an $allowed_children directive!
Boy I had a hard time debugging this.
Turns out, in the _config.php located in /cms/ there is this line:
Director::addRules(50, array(
'processes//$Action/$ID/$Batch' => 'BatchProcess_Controller',....)
So "processes" is actually a reserved keyword.
Just in case someone has the same idea...Rename your holder class "processesHolder" or "procedures"