This was a 4.0-4.1 issue from my recollection.
Well without running your cron task your ads never expire or auctions never end. That in itself if you disable it would create a huge issue if you ask me but thats up to you.
You can turn off the cron in admin if you are using the footer cron task. If your using the server cron task that is something you setup in your server cron task list and you need to remove at server level there is no program switch for that.
The proper action here is to upgrade. I can only give you answers based on a support perspective.
You could theoretically download the latest code and replace your cron.php and sendnotice.php files. They are self contained files so updating just those two should be fine.
The problem with most people when they say they upgrade is piece meal things. Meaning you can say your using 5.1 but theoretically if you did not start with a base 5.1 core and say upgraded you could still be running 4 series cron scripts if you forgot to replace those files.
Another aspect to consider here is were all required upgrades done. There is a field in your cp_stats table called lastupdate and there should be an entry in that table that has a unix timestamp of when the last time the cron task was ran.
I would suspect if those files where current you would not have any issues.
Last edited by Chuck S; December 21st, 2012 at 04:59 PM.