[Zope] 'Delete objects' permission

[Tim Terlegård]

Are permissions handled differently on folders than other objects?
I have a community site where members should be able to add objects
anywhere, but only delete their own objects. How do I achieve this?

I have a folder and in it an object. If I add 'Delete objects' and
'Modify portal content' for Owner on the object I still can't delete
it. If I add 'Delete objects' for Owner on the folder I still can't
delete the object, but if I add 'Delete objects' for Member, then
I can delete the object.

How should I set the permissions to get this community policy?

I've searched The Zope Book, Zope mailing lists and google without
finding an answer. Maybe there isn't one  ;-)

Thanks, Tim