[Samba] problem with created file permissions

[John W]

After struggling with my smb.conf for a while, I feel I am missing
something fundamental about how 'create mask' and 'force create mode'
work.

I have a dropbox-style share (which is working), which uses 'security
= share', and I would like to specify certain permissions on files
created in this share.

In both of the below examples, files always get created with 744
permissions ('-rwxr--r--').

# example 1
[myshare]
 comment = my share
 path = /path/to/myshare
 public = yes
 read only = no
 writable = yes
 browseable = yes
 printable = no
 force create mode = 0777
 create mask = 0777

# example 2
# identical to the above, except for the last two lines, which are instead:
 force create mode = 0000
 create mask = 0000

Is there a piece of the puzzle I am missing here?
I don't actually want the above permissions ultimately, of course, but
hopefully they demonstrate that I am failing to get it to work at all.

This is samba 3.5, running on FreeBSD 7.2-RELEASE.
I can provide more details of my smb.conf, if that will help.

Sorry if this seems very basic, but my own research is not proving helpful yet.

Thanks
-John