samba - Jan 2001 - odd file/directory permissions issues between Win NT (and 2K) and Samba 2.0.7

Folks,

this one is baffling me:

I have a parent directory (mode 777, not owned by me) that contains a
directory called foo (owned by me), which in turn contains files. I created
this folder by copying over from Windows to a Samba server in User Mode,
logged in as user Hug0.  This yielded a dir with our standard mask; fine so
far!

2 drwxr-xr-x  2 Hug0  user  512 Jan 20 11:54 foo

I can go to the directory in WinNT Explorer and select
properties->Security->Permissions, and I see the permissions correctly
reflected. I can change the rwx bits for myself (Hug0) using this method.
However, if I try to make the dir group writable (so someone else can move
it somewhere else), it doesn't stick; no error messages from NT (just a few
quick messages from the Explorer that are unreadable when I close the
Directory permissions windows).  No debug messages are emitted from samba.
Interestingly enough, if I chmod 775 the dir in Unix (as user Hug0) and then
go back to the properties tab, I can see that there are write privileges. I
can then take away the write privilege, but then I can't add them back!!

Any idea what's going on here? Also, which of the  read/write/execute
properties work under Win2K? I get ACE errors in the samba log when we use
them.

Many thanks,

Craig