by Robert Malpas.
Well, I took the plunge and deleted the first line in the task_adhoc database as shown in the previous post that seemed to be causing the problem. And once that was done, all the ad hoc tasks cleared themselves, I no longer get an error message in the cron report, and my automated back-ups are all running fine again. Only time will tell whether there are any long term issues arising from this, but all looks good for now at least.