Help with check_ntp_time v1.4.15

I have an interesting situation in which check_ntp_time is returning "NTP
CRITICAL: No response from NTP server".  This is odd because the NTP server
is reachable from the host which is getting time from it successfully.

Here is an example of the plug-in failing to contact the server, and
ntpdate running an updating time successfully.

[root@stripedmarlin ~]#
/opt/app/nagios/nagios_plugins/current/libexec/check_ntp_time -t 30 -H
ext-timekeeper.schoolspecialty.com -w 1 -c 2
NTP CRITICAL: No response from NTP server
[root@stripedmarlin ~]# ntpdate ext-timekeeper.schoolspecialty.com12 Jul
16:36:29 ntpdate[6233]: adjust time server 10.14.99.68 offset -0.003131 sec

Do you have any suggestions as to what may be going on?  This is a RHEL 5.8
x86_64 VM.

Thank you,
Ken Edgar
Unix System Administrator - School Specialty, Inc.

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