Hi Ken,
Looks like they changed the call variables. Look for something like this in backup/controller/backup_controller.class.php
// Basic/initial prevention against time/memory limits
set_time_limit(1 * 60 * 60); // 1 hour for 1 course initially granted
This is from Moodle 2.5 build so hopefully they have not changed it in 2.6 . Maybe do a search for "1 hour for 1 course" or "60" which is what I normally look for when modifying it between relelases.