Comment 14 for bug 157608

You can add this line to the file /etc/ntpd.conf to see what happen :
logfile /var/log/ntpd

On my Gutsy, I see an error like that :
 1 Apr 08:48:25 ntpd[5642]: couldn't resolve `fr.pool.ntp.org', giving up on it

Because when ntpd starts, the eth0 interface is not yet started (because of dhcpd), so ntpd just gives up...