After booting ubuntu server 9.04, and after I login on the terminal, I am getting the message over my terminal "Stopping NTP server ntpd" immediately followed by "Starting NTP server ntpd" about every 20 seconds.

What is causing this? How do I stop it without disabling the ntp server? Is there a more useful log than /var/log/daemon.log that I could be looking at?

This is a section of the output from daemon.log:
Jul 20 13:39:02 cyclops-9999 ntpd[3569]: ntpd exiting on signal 15
Jul 20 13:39:02 cyclops-9999 ntpdate[3605]: adjust time server 91.189.94.4 offset -0.071625 sec
Jul 20 13:39:02 cyclops-9999 ntpd[3633]: ntpd 4.2.4p4<at>1.1520-o Wed May 13 21:10:45 UTC 2009 (1)
I have a wild theory that is based on my editing of the /etc/network/interfaces file. The total number of times that it prints to my terminal seems to be the same as the number of active network devices I have.