I just spent bloody forever trying to force any folder created by a Windows user to automatically be 770 instead of 750 on a Samba share (3.6.2 on Ubuntu).
The issue at hand is, with force directory mode = 0770 if a user creates a folder DIRECTLY on the Samba share, all is well… but if they drag an already existing folder FROM their windows machine INTO the samba share, it ends up 0750 and nobody else can see it. (I don’t want to tell you how long it took me to figure out WHEN, exactly, the mode wasn’t getting set correctly, either.)
I chased my tail with masks, directory security mode, unix extensions, and more, before I finally, FINALLY found the fix:
edit /etc/login.defs and set the default umask to 002 instead of 022. *poof*, problem solved. Thank you, thank you, THANK you, random dude from ubuntuforums.org…