valid-users not working in samba-1.9.18p10

[Christoph Doerbeck]

I have the following snippets in my smaba.conf :

    netbios name = velours
    server string = PDS Samba %v
    security = server
    password server = bdcfoo.bar.com
    null passwords = no
    username map = /opt/samba/lib/users.map
    hosts allow = @dis_nt @dialin
    hosts deny  = ALL

[homes]
    .
    .
    . <snip>
    .

[y2k]
    comment = share for year 2000 testing
    path = /
    hosts allow = @dis_nt
    valid users = johndoe,janedoe
    writable = no
    browseable = yes

In a previous life, running samba-1.9.17p4, a user in our NTdomain could
seemlessly connect to any share (@netgroup, and "valid users =").
Since I've upgraded to p10, the y2k share requires a reauthenticated login
unless I remove the "vaild users" line.

Once it is commented out, everything works seemlessly again, but now everyone 
on a machine in NTdomain & Netgroup can get access.

This setup worked properly with samba-1.9.17p4.  Any comments, suggestiong,
or bugs I should be aware of?

########################################
#  Christoph Doerbeck