[newbie] Cron fails after a day or so..

I have had a single cron job that monitors my ip address running for quite some time on my box with no problems. A few days ago, I added a second job to run "rdate -sp time.nist.gov" at specifc intervals. It seems that after a day or so, both jobs stop ( no email to root ), and crond returns

[newbie] Cron fails after a day or so..

I have had a single cron job that monitors my ip address running for quite some time on my box with no problems. A few days ago, I added a second job to run "rdate -sp time.nist.gov" at specifc intervals. It seems that after a day or so, both jobs stop ( no email to root ), and crond returns