Every time I request a permission change the IT group at my company instructs me to wait 20 minutes and reboot the computer. I cannot believe that in this day and age you still need to reboot the computer to clear whatever cache stores the permissions locally. It feels like something out of the NT 4 days. 

* Do you actually still need to reboot the computer?
* Is a logout/login sufficient?
* Is there still a long time(20 minutes) for the changes to propagate through the AD tree?