Some quick poking around in the Red Hat archives seems to show a general consensus that the “Alarm clock” output seems to simply be an oddly named error message for timed out, or unable to acquire time. One of the threads discussing this matter can be found at:
http://www.redhat.com/archives/fedor.../msg00768.html
My suggestion would be to either try syncing with a different server, or possible try using the ‘ntpdate’ command. It may or may not work, but if it should fail you might get a slightly more useful error message.