Windows 8 Group Policy Preferences Local Users and Groups, error 0x8007052a

I am testing an existing GPO Preference with Windows 8 that renames the Builtin Administrator account and sets the password.  It works on XP and Win 7 but not on Win 8.  RSOP reports that the GPO completed successfully but provides the following additional information:

Group Policy Local Users and Groups completed successfully.
Additional Information:
The computer 'Administrator (built-in)' preference item in the 'Test_Policy {guid}' Group Policy Object did not apply because it failed with error code '0x8007052a This operation is disallowed as it could result in an administration account being disabled, deleted or unable to logon.'%%100790273

Sounds like there is a setting somewhere that is preventing changes to the builtin administrator account, but I can't find our where it is to toggle it off.  Any ideas?