Group Policy won't work unless domain admins

[ShaneUK20]

Hi

I've created a GPO to allow my Outlook 2007 to be programmatically accessed
by a database. It works beautifully if the user is a member of the domain
admins but it fails if they are simply users.

The GPO makes various changes in User Config/Policies/Admin
Templates/Microsoft Office 2007/Security.

I've checked that they can apply other GPs and it works even when they are
simple Domain Users.

There seems to be something that prevents me from lowering the levels of
security for users but not for Admins.

Any help would be much appreciated.

Many thanks

Shane