Hi,
I finally found the culprit. In our workflow, I removed all of the 4 workflow permissions (Access contents information, Change portal events, Modify portal contents and View) from the Member role on all states but internally_published. I'm currently having a thorough look at the documentation on docs.plone.org (which was not as comprehensive as today when I started with Plone) in order to fix / avoid such problems.
Restoring Access contents information, as suggested by Dieter, solved the problem.
But this leads me to another questions:
- how comes that this property missing from the Member role prevented people having this particular permission as Owner to delete (and only delete) objects?
Thanks in advance,
phep