I recently came across an "Access is denied" issue when I was trying to disable the SID filtering in Windows 2008 side.
Anyway, this is what I did to resolve the issue:
I have enabled the "Network access: Allow anonymous SID/Name translation" GPO settings in "Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\Security Options".
I have performed this action only in my Windows 2008 Domain.
Also, please read the following articles and make sure you understand policy details before enabling it.