Filtering Group Policy Preferences via a Security Group

Hi,

I was wondering if you can help me.

I'm trying to roll out a simple desktop shortcut via GPP (its a user Policy), which works fine when I allow the default "authenticated users" within Scope\Security Filtering

However, when I remove this and replace it with a Security Group (to restrict who gets the shortcut on their desktop) it ceases to work.

BUT, if I remove the security groups and manually define each user in the scope\security filtering it works fine.

I am using Server 2008R2 for Domain Services and the client machines are all Win7 Professional.

Any help would be fantastic.

Peace