GP Locks out Adding Desktop Icons

I'm a learner to Server 2003 Group Policy editor and am configuring a lockdown for users in our centre, so that they can add shortcuts to the desktop. They need to be able to do this for their course. Somehow, users can not do this and no matter what I try, I can not make it so that they can add icons to their desktop.

The user group get their desktop icons from the server, and when the shortcut sets are not pulled from the server, they can add to the desktop. Unfortunately, however, the shortcuts they need to use are not available.

In User Config/Folder redirection/Desktop, the PC pulls down the desktop settings from the server and does not grant the user exclusive rights to the Desktop.

In terms of the rest of the GP settings, I have the following that pertain to the desktop.

Active desktop wallpaper - Enabled
Enable active desktop - Enabled
Don't save settings at exit - Enabled

Am I missing something really obvious here? I would be very grateful for any advice on how I can allow my users to complete their course!

Many many thanks,

Vicky