I may be having a different problem than other posters on this bug report. My internet connection is a WPA-secured wireless connection. The interface is brought up at boot time, and NTP is started. However, the wireless card does not connect to the router before I log in and enter my keyring password (which unlocks the WPA password). At that time, ntpd has already figured out that it cannot connect to any of the time servers:
Oct 7 14:17:43 localhost ntpd_initres: couldn't resolve `ntp.ubuntu.com', giving up on it
Now, when the wireless interface connects to the router and gets configured via DHCP, NTP does not do anything anymore.
I guess that most people using laptops with WPA-secured wireless networks suffer from the same problem. I believe the default configuration should work with this kind of setup (as it appears to be increasingly common).