Philip, are you speaking of unix cron? This thread was about the cronjob package, not related to unix cron. However, to suspend a job, which runs under your user account, do:
You will probably be in vi to edit, so 'arrow' down to the line you want to suspend and then type 'i', then '#', to comment out the line. then type ':wq' to save and exit.
In the cronjob package you can also disable a cronjob.