samba - Jul 2002 - Problem with permissions on share

Hi!

I have two issues that troubles me, hope you can be so kind to enlighten a
newbie...

1) We have problems with setting the desired permissions on the test share. 
When we set the permissions (UNIX) to

drwxrws---

on the share directory, we are not able to map it on the PC (W2000). The
directory is set belong to a NT group that my NT user is a member of, and I
thought that should be enough to make the mapping possible, based on the
group rights that is. If not, the whole idea of sharing and possibility of
restricting access is lost. When we make the share globally open
(drwxrwxrwx) , mapping is no problem. What clue(s) are we missing here?

2) How and when are the $LOCKDIR/winbindd_cache.tdb and
$LOCKDIR/winbindd_idmap.tdb updated? We made a new NT test group, was able
to look it up, but when trying to convert the SID to a UNIX group, we got
the "could not convert..." message.

Cheers,

Viktor