[Samba] Winbind and its log message

[Hai Wu]

The server is a NT 4.0 domain member server. It uses Winbind.

Everytime I login to the system using system local user, such as root,
it says this:
[2004/04/21 11:01:39, 1]
nsswitch/winbindd_group.c:winbindd_getgroups(954)
  user 'root' does not exist

Everytime I tried to switch to another local user, such as "su bb", it
would say in /var/log/messages:
[2004/04/21 10:59:15, 1]
nsswitch/winbindd_group.c:winbindd_getgroups(954)
  user 'bb' does not exist

Is this a normal behavior? Or is there any setting that would turn these
messages off?

Thanks,
Hai