[Samba] Folder permissions not working

[Mike Bryce]

I seem to be having a bit of a brain fade with regard to permissions in 
samba. I have a share with several folders owned by different groups:

drwxrws--- 13 root     accounts     4.0K Jun  7 12:12 Accounts
drwxrws--- 16 ian      accounts     4.0K Jun  7 11:24 Administration
drwxrws--- 14 accounts users        4.0K Apr 22 12:05 Downloads
drwxrwsr-x  7 ian      users        4.0K Mar 22 13:51 Graphics
drwxrws--- 14 marion   admins       4.0K Jun  6 14:39 Ian & Marion
drwxrws---  5 ian      myob         4.0K Jun  5 12:02 MYOB Accounts
drwxrws--- 41 ian      users        4.0K Jun  4 16:03 Plant Health
drwxrwsr-x  8 ian      users        4.0K Jan  8 07:49 Research
drwxrws--- 12 ian      users        4.0K Apr 16 16:57 Staff
drwxrws--- 21 ldapuser coffeecentre 4.0K Jun  5 13:32 The Australian 
Coffee Centre


I have a user (marion) who is a member of all these groups and more:

# groups marion
admins users coffeecentre accounts domadmins domusers myob

The issue is, Marion can't access the folder called "The Australian 
Coffee Centre", Windows 7 says no permission and the samba server shows:

# tail /var/log/samba/log.marionhome-pc
[2013/06/07 08:28:31.144321,  1] 
smbd/service.c:805(make_connection_snum)
   create_connection_session_info failed: NT_STATUS_ACCESS_DENIED
[2013/06/07 08:28:31.240024,  1] 
smbd/service.c:805(make_connection_snum)
   create_connection_session_info failed: NT_STATUS_ACCESS_DENIED


All other sub-folders in this folder are accessible as expected. Where 
do I need to go looking for this problem? Anyone struck this before?

Happy to provide further info as directed.
-- 
Have a Nice Day!
Mike