MindTouch 10.0.8 with php 5.3.3, navigating to Extensions > Add Script renders a blank page, and no errors thrown in the apache log.
It looks like PHP 5.3 has different behavior for call_user_func_array, change MINDTOUCH/deki/cp/extensions.php:189 to warp the parameter as an array:
$this->executeAction('add', array(true));