[NTLUG:Discuss] ntpdate -vs- cron

[Egome]

I do not know why these two programs have SUCH a difficult time working
together on my Slackware 7.1 server!

If I execute /usr/sbin/ntpdate time.nist.gov  from the command line,
everything works beautifully!

If I try to make a cron job of that command line I get the following error
message emailed to root..

ntpdate[3103]: the NTP socket is in use, exiting


I've tried sending the output to /dev/null, ( /usr/sbin/ntpdate
time.nist.gov >> /var/log/ntpdate.log > /dev/null ) but it still get's
emailed to me.

Why does the command work from the command line but not as a cron job?