[Samba] mac osx users have files written with non group permissions for some reason

[Harondel J. Sibble]

I have a strange problem I am hoping some one can help with, pc and linux 
users all work fine accessing, modifying, adding and deleting files, but 
anytime a mac user touches a folder or creates a new one, it gets restricted 
to just their own use

This is a Debian 5 system with Samba 3.2.5, the mac's are all running OSX 
10.5.x

Relevant share info

# read/write area on server (accessible to all users)
[mainshare]
        browseable = yes
        writable = yes
        path = /srv/samba/mainshare
        comment = All User Access 
        valid users = @users
        force group = users
        force create mode = 0660
        force directory mode = 0771

Using any of the other mask or directory options in smb.conf has zero effect, 
best I can tell by lots of testing, these get completely ignored and the 
directory and file gets written with 755 permissions.  This locks out the 
windows, linux and other mac users :-(

I found someone else with a similar problem here

http://www.experts-exchange.com/Software/Server_Software/File_Servers/Samba/Q_23571514.html

or

http://preview.tinyurl.com/ydox957

Before I fire up wireshark, anyone else experiencing this and how did you 
solve it?
-- 
Harondel J. Sibble 
Sibble Computer Consulting
Creating Solutions for the small and medium business computer user.
help at pdscc.com (use pgp keyid 0x3AD5C11D) http://www.pdscc.com
(604) 739-3709 (voice)