Loopback GPO for Citrix is not working

Hello,

I am trying to apply my first "loopback" policy on my Citrix server. The policy I want to implement is to hide the Citrx server's local drives (C&D)

I have read several articles on how to do this, and followed them step-by-step but can not get it to work. Here is what I have done:

1. I created a new OU and moved a Citrix server in there. (I have other Citrix servers but for now I only want the local drives on this one hidden.)

2. In this OU, I created a GPO called "Loopback." User configuration has been disabled and "User group policy loopback processing mode" has been enabled and set to "merge."

3. Next, I created another GPO called "Hide Local Drives" and it is linked to the same OU the Citrix server is in.

4. Computer configuration settings have been disabled for this GPO and the setting to hide drives A though D has been selected.

5. In the security tab of the “Hide Local Drives” GPO I unchecked “Read” and “Apply Group Policy” for Authenticated Users I added two test user accounts and checked  the “Read” and “Apply Group Policy.” (Note, these test user accounts are in another OU and used just for testing.)

6. On the Citrix server, I ran  “gpupdate /force” and even restarted the server and still cannot get the loopback policy to work. If I link the GPO directly to the OU where my test user accounts, the GPO works but then it hides even the local drives to workstations (defeating the purpose of the loopback.)

Any suggestions as to what I may be missing?

A little bit about what I'm working with:
Citrix XenApp 6.0 running on Windows Server 2008 64-bit