[Samba] Very strange permission problem: samba on zfs-fuse

[Fajar Priyanto]

Hi all,
Centos 5.7
samba-common-3.0.33-3.29.el5_7.4
samba-3.0.33-3.29.el5_7.4
zfs-fuse-0.6.9_p1-6.20100709git.el5.1

smb.conf
[depot]
path = /data/depot
public = no
writable = yes
directory mask = 2775
create mask = 0664
vfs objects = recycle
        recycle:repository = .deleted/%U
        recycle:keeptree = Yes
        recycle:touch = Yes
        recycle:versions = Yes
        recycle:maxsixe = 0
        recycle:exclude = *.tmp
        recycle:exclude_dir = /tmp
        recycle:noversions = *.doc

I have asked this in zfs-fuse list, but still in discussion....

I have setup this samba share on a zfs-fuse filesystem.
drwxrwsr-x 16 backup userlab 27 Nov 28 10:12 depot

All samba users are secondary member of 'userlab' group.
(usermod -G userlab user1, etc)

The problem I have is that after some time, some users begin
experiencing permission denied when try to put files or create
directories on the samba share.

smbd.log shows:
[2011/11/28 10:13:29, 2] smbd/open.c:open_directory(2092)
  open_directory: unable to create New Folder (2). Error was
NT_STATUS_ACCESS_DENIED
[2011/11/28 10:13:29, 2] smbd/open.c:open_directory(2092)
  open_directory: unable to create .. Error was NT_STATUS_OBJECT_NAME_COLLISION
[2011/11/28 10:13:29, 2] smbd/open.c:open_directory(2092)

Strange thing is, I experimenting by making 'userlab' as my 'fajar'
user's primary group (usermod -g userlab fajar). And my 'fajar'
account doesn't have this permission denied problem. I don't know yet
if this is a permanent fix or not.

Does anyone has ever encounter this problem?

Thank you,
Fajar.