[Zope] Problem with DTML document properties

Hello, I'm trying to change properties for all files, folders and DTML documents in a folder. When I do <dtml-with "folder"> or <dtml-with "file"> and then <dtml-call "manage_changeProperties({'title': 'new title'})"> then it works. But for DTML document, it will try to change either current folders or current DTML document's property. Is there any restriction or smth? Sven