[Samba] Permissions problem - I am in the proper group but still can't create files

[Ryan Stille]

I have a share created on my linux server.  I can connect to it with the 
"administrator" user just fine.  I need to be able to create files and 
directories with the administrator user, even in directories that are 
not owned by administrator.  administrator is in the users group.   
Everything under the share is in the users group, and the group has 
write permission.  So why can't administrator create files?

If I chown the parent to administrator, then it works fine.  But 
administrator is in the group, and the group has write permission.  So 
why does it also have to be owned by administrator?  I don't have this 
issue on all my other linux servers, just this new one (CentOS 5.2).

Here is the folder I'm trying to create a file in:
drwxrwxr-x 2 root          users  4096 Jan 28 11:10 foo

Here is the line from /etc/group:
users:x:100:rps,administrator,root

And here is my samba share:
[websites]
   comment = /home/WWW-data
   path = /home/WWW-data
   read only = no
   valid users = rps administrator
   create mask = 0664
   directory mask = 0775
   force user = administrator
   force group = nobody

Thanks for any help.
-Ryan