Ubuntu Servers :: Samba Users Able To Browse Folders With No Permission

I've set up smbd 3.4.7 on 10.04x64 LTS server. I've set up a couple shares and I'm having problems blocking access to certain directories using native file permissions. There is one directory that has folders for each sales rep to store their current list of quoted clients, I only want sales people to be able to browse the directories owned by themselves. Everything seems to be set up correctly in terms of user groups and permissions on the filesystem.

Below is marina, a sales rep, and brian, a super user of sorts.
id marina:
Code:
uid=1011(marina) gid=1006(office) groups=1006(office),1005(sales)
id nick:
Code:
uid=1000(brian) gid=1006(office) groups=1006(office),118(admin),1001(full),1002(processing),1003(management),1004(it),1005(sales)

Below is the directory with all the sales reps folders.
ls -la:
Code:
total 60
drwxrwxr-x 15 root it 4096 2011-02-10 20:06 .
drwxr-x--- 9 root office 4096 2010-11-19 12:40 ..
drwxrwx--- 13 katya full 4096 2010-12-07 12:36 Katya
drwxrwx--- 18 lana full 4096 2011-02-08 17:09 Lana
drwxrwx--- 23 marina full 4096 2011-02-10 18:09 Marina
drwxrwx--- 4 mike full 4096 2011-02-01 12:42 Mike

With this setup marina only be able to browse her folder, but she can browse all folders and has full write access to all folders. This leads me to believe something is up with the smbd.conf file, which is below.

Code:
[global]
workgroup = COMTREAD
null passwords = no
server string = Root Server
dns proxy = no
log file = /var/log/samba/log.%m
max log size = 1000
syslog = 0 .....

In this case the valid users directive would not work cause I am not making a share for each user. I had this on other shares like the db2 share. My windows box lagged heavily when I tried to access that share with an invalid user. How to deny users the ability to modify permissions I would also like to do that.