Linux server time getting out of sync frequently.

[unix syzadmin]

Time on my linux server gets out of sync.  The ntpd service is setup... and
we have configured /etc/ntp.conf accordingly.
This is the only linux server that is having this problem.  Also some
times... I find ntp service is dead. Please suggest.

# service ntpd status
ntpd dead but pid file exists


# date
Tue May 27 02:52:44 EDT 2008

# ntpdate -u ntpserver
27 May 08:41:37 ntpdate[10330]: step time server 10.38.9.74 offset
20927.946559 sec

# date
Tue May 27 08:41:38 EDT 2008

# more /etc/redhat-release
Red Hat Enterprise Linux AS release 4 (Nahant Update 5)

# uname -a
Linux srvr017 2.6.9-55.0.2.EL #1 Tue Jun 12 17:47:10 EDT 2007 i686 athlon
i386 GNU/Linux

# rpm -qa | grep tzdata
tzdata-2007f-1.el4