I need some clarification of groups(PDC and local unix groups)

[Scott Shealy]

(I have been searching for 2 days now for an answer so please forgive me if
this has been answed many times)I am trying to set up a samba(2.0.7 on Linux
2.2.17) fileserver for our domain. It is not the PDC. What I want is to
create a share that some people can only read and others can read and write.
Currently what I have done is configued three local groups on the linux
samba box.  One group ntuser everyone is a member of and it is there primary
group in the /etc/passwd. I have defined two other groups partime(for part
time staff) and fulltime (for full timestaff) and placed the appropiate
people in them in the /etc/groups file.  I want the partime people to only
be able to read and the full time people to read and write all files in that
share.

Here is what I tried
[global]

   workgroup = OURDOMAIN

   server string = OURSamba Server 
   security = domain
   password server = ourpdc

[IntraNet]
   comment = IntraNet
   path = /IntraNet
   admin users = adminnt
   valid users = @ntuser
   read only = yes
   write list = @fulltime
   force create mode = 0774
   force directory mode = 0775
 
But this doesn't work right.  The domain stuff seems to be working ok. Other
simpler shares are working fine with domain authentiation. Can anybody tell
me how to accomplish this. Does Samba ignore local groups when
security=domain?  Does it only look in the primary group(the one set in
/etc/passwd).  Anyway I missing something here.  Could someone please
explain this to me.

Thanks,
Scott Shealy