I have the same issue. SharePoint Explorer view won't let you move or delete any content. You can create new content with no issue. I've tried the registry changes for loosening the removable media definition, per the Admin guide. This was suggested by a friend of a friend who is a McAfee guru. It did not fix anything.
Does the Sharepoint version matter? I know we are on 2003. This is EEFF 3.2.5 and it's EEM managed. We have the policy set with no items checked for network resources.