Problem faced while defining permissions for read & wirte access

[FRANCO FERNANDES]

Hi!
I have got a requirement of defining a share,where one user should have
reader rights & other should be having write rights.The definition is as
below

comment = Testing Permissions
path = /usr/local/support
valid users = ibm, god
read list = ibm
write list = god
read only = No

when i define this the user=GOD gets permissions properly i.e=write
But the user=IBM also gets write permissions instead of read.
I have relaxed the permissions on unix by giving 0777 to the path

i.e drwxrwxrwx 3 root root 4096 Oct 9 11:53 support


This happens to every share which i create & my smb.conf file is tested
from the diagnosis.txt

Is there any thing which I am missing
Please revert to me asap

Thanks in advance
Franco.F