[Samba] Can't get 'dos filemode' to work as expected

[Felix Brack]

Hello,

After an upgrade to samba 3.5.8 (from 3.2.5) the option 'dos filemode' 
does not seem to work anymore. If I (as a user) do not own the file I 
can't change permissions.

I am user 'felix' and member of supplementary group 'Development'. To 
test things I use the following share definition:

[Temp]
         path = /srv/samba/file-shares/tmp
         browseable = yes
         read only = no
         invalid users = root administrator
         delete readonly = yes
         inherit owner = yes
         force group = Development
         dos filemode = yes

A 'getfacl' on /srv/samba/file-shares/tmp returns:

# file: srv/samba/file-shares/tmp
# owner: root
# group: root
# flags: -s-
user::rwx
group::r-x
group:Development:rwx
mask::rwx
other::---
default:user::rwx
default:group::r-x
default:group:Development:rwx
default:mask::rwx
default:other::---

 From the 'smb.conf' man page concerning option 'dos filemode':

...
Enabling this parameter allows a user who has write access to the file 
(by whatever means, including an ACL permission) to modify the 
permissions (including ACL) on it.
...

My understanding: as a member of group 'Development' I do have write 
access to '/srv/samba/file-shares/tmp' by means of the ACL.

Trying to modify permissions on a directory or file I create in that 
share does not work and reports access denied, no matter if I use 
Windows Explorer or smbclient from an other linux box.

What am I misunderstanding here?

Many thanks, Felix