Can only be said when seeing your ntp.conf file (egrep -v '^$|^#' /etc/ntp.conf). What does "ntpq -p" tell you?
Here's some output:
[charshaw@localhost charshaw]$ egrep -v '^$|^#' /etc/ntp.conf restrict default ignore restrict 209.132.176.4 mask 255.255.255.255 nomodify notrap noquery restrict 127.0.0.1 server 66.187.233.4 fudge 127.127.1.0 stratum 10 driftfile /var/lib/ntp/drift broadcastdelay 0.008 authenticate yes keys /etc/ntp/keys
[charshaw@localhost charshaw]$ /usr/sbin/ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
clock1.redhat.c 0.0.0.0 16 u - 64 0 0.000 0.000 4000.00
