Invalid Permissions setting

[janhsh]

I create a directory to which I assign the following rights
Admin: Write + Share
CD:: Write
Member: none (present without box checked)

Users of the "Member" group have access to the directory and can only read.

But the users who are in the group "CD" and also in "Member" only have access to the directory for read whereas it should normally be able to write there (since they are also in "CD")

Same for the user who is "admin" + "CD" + "Member", he does not have write access either