[Samba] Samba ignores write and read list

[stingray at zsgutova.cz]

Hi everybody,

I have problem with samba and really don't know how to solve it.

Seems as if samba ignored write list and read list options in smb.conf. 
Because when I have
writeable = yes
read list = dummy
user dummy can still write/delete. When I try to do it opposite, i.e.
read only = yes
write list = dummy
then dummy cannot write.

The point is, I have bunch of users specified by valid users (works ok) 
and few of them will have read-only access, the rest read-write access. 
I need to do it on samba level, not by unix rights.

Version of samba: 3.0.20
System: FreeBSD 4.9-RELEASE

Config file:

==========================================
[global]
netbios name = FreeBSD
server string = "FreeBSD Server"
workgroup = GROUP
security = share
log file = /var/log/samba.log
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
encrypt passwords = yes
wins support = yes
local master = yes
domain master = yes
preferred master = yes
os level = 50
force create mode = 0766

[ALL]
path = /data/all
public = yes
guest ok = yes
writeable = yes

[SEC1]
path = /data/SEC1
public = no
writeable = yes
valid users = mike bill

[SEC2]
path = /data/SEC2
public = no
valid users = mike john
writeable = yes
read list = john
==========================================

SEC1 works ok, SEC2 has problems described above. Testparm passes with 
no problems.

Thank you in advance for any idea how to solve it.

Best regards

Roman