nscd did not answer queries for passwd entry for root and sshd from time to
time, so no login is possible to the machine anymore.

Probably related to
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=574990

As files is before libnss-ldap (see below) nscd should be able to answer even with
ldap unavailable.

"reportbug nscd" did not show the bug mentioned above, which may be a bug
in nscd packaging or reportbug itself.

Thanks,
   Hermann
---------------------------------------------------------
cat /etc/nsswitch.conf
passwd:         files	ldap
group:          files	ldap
shadow:         files	ldap

hosts:          files dns
networks:       files

protocols:      db files
services:       db files
ethers:         db files
rpc:            db files

netgroup:       nis