I got burnt by these errors in the .adm and/or .opa files, so I thought I'd post them here:

http://support.microsoft.com/kb/935734/en-us

The "Prevent users from adding PSTs to Outlook profiles and/or prevent using Sharing-Exclusive PSTs" setting is configured incorrectly in the Office Customization Tool and in the Group Policy templates

http://support.microsoft.com/kb/935733/en-us

Cached Exchange Mode is enabled in Outlook 2007 even though you set the "Do not use Cached Exchange Mode for all new Outlook profiles" setting in the Office Customization Tool

http://support.microsoft.com/kb/936979/en-us

The "Make Outlook the default program for E-mail, Contacts, and Calendar" setting is disabled in Outlook 2007

Also, this article was useful to disable the DRM UI:

http://technet2.microsoft.com/Office/en-us/library/b2869a87-5f86-4c7d-ac5f-808db138b2131033.mspx?mfr=true