Until 9.1R7 PCS was using ntpdate protocol for NTP time synchronization. Because of that Administrator was able to see message:
"Server 'x.x.x.x' is unreachable or the symmetric key provided is incorrect" in Event Log.
Since 9.1R8 we replaced ntpdate for ntpq. Since then, information "Server 'x.x.x.x' is unreachable or the symmetric key provided is incorrect" no longer exist and it was replaced by information:
"Unable to synchronize time, either NTP server(s) are unreachable or provided symmetric key(s) are incorrect."
As a standard of new process this information has been moved to Admin Logs as Administrator should be aware of this situation.