If the setting "restrictmodulesfor" is set to "all Courses" in Moodle 1.9 (Security->Module Security)
there will be a mayor issue in upgrade step from 2.2 to 2.4.
See lib->db->upgrade.php starting from line 230 ($oldversion < 2012031500.01).
In my case nearly every activity module will be disabled to add (:addinstance) to a course from "teacher" role.
I think, it is better to follow the settings from the course ("$courses = $DB->get_records_menu('course', array('restrictmodules' => 1), 'id', 'id, 1');") directly (and not "if ($CFG->restrictmodulesfor === 'all')").
The german translation of the setting "restrictmodulesfor" in 1.9 ("Welche Kurse sollen die Einstellung zum Deaktivieren von Lernaktivitäten haben? Beachten Sie, dass diese Einstellung nur Trainer/innen betrifft. Administrator/innen dürfen weiterhin alle Aktivitäten zu einem Kurs hinzufügen.") only means, that the ability to disable modules in single courses is given.
But now in my actual Moodle 2.4 nobody (teacher) has the ability to add i.e. quiz activity to a course.
See my Workaround attachment.

I hope you understand my formulation and forgive me for my bad english.

kind regards from Salzburg