Cron Job - cron tabs

the otrs cron file disappeared from
/var/spool/cron/tabs
so i had to add the file back in there.
I wonder if i have this setup wrong or was it just a once off thing?
anyways i will monitor it and if it happens again i will reconfigure the cron.

SLES 10 sp1 OTRS - Cron Jobs

after setting up a new OTRS installation (www.otrs.org)
I had to setup a cron job to pop emails from our server to check for new tickets.
This website helped - http://en.opensuse.org/SUSE_Package_Conventions/Cron_Jobs

Cron Job to setup was listed on the otrs website
i added in

# --
# cron/postmaster_pop3 - postmaster_pop3 cron of the OTRS
# Copyright (C) 2002-2003 Martin Edenhofer 
# --
# $Id: installation-and-basic-configuration.xml,v 1.10 2006/09/07 13:15:07 cs Exp $
# --
# This software comes with ABSOLUTELY NO WARRANTY.
# --
# fetch emails every 10 minutes
*/10 * * * * $HOME/bin/PostMasterPOP3.pl >> /dev/null
# --

to the file
/var/spool/cron/tabs/otrs