The ntp package installs a start/stop script called "/etc/rc.d/ntpdate". The corresponding configuration file in /etc/conf.d, however, is called "ntp-client". Similarly, the start/stop script registers a running daemon (why?) that's called "ntp-client", so the system tries to access a start/stop script of that name during shutdown, which doesn't exist, resulting in an error.

To remedy the situation, the "ntpdate" script should be renamed to "ntp-client", or the name of the config file and the name of the daemon should be renamed to "ntpdate".