Hi there... which version are you running?
In 6.0.11 you need to edit start.php and prior versions you need to edit run.php and find..
//$reportico->initial_show_criteria = "show";
and change it to :-
$reportico->initial_show_criteria = "hide";
In the older versions .. you would need to refresh the session to pick up the change by reinitiating index.php ..
Let me know if that helps .. or not!