Back in November I added '-once' to the BLP report that was behind the multiple jobs (it runs every 5 minutes, but with the 'once' command can only create one job at any time).
The backlog of jobs was an unexpected problem as the report had been running in a stable state for a year before the job-glitching, no doubt itself caused by a problem elsewhere. The report did seem to be taking a ridiculously long time to complete (like 40 times longer than it used to). Possibly this is down to a database change I am unaware of, but that can be sorted out with a separated discussion on an email list.
Could the throttle please be removed or changed? As a result of the throttle the BLP report which was being used by several administrators as an important vandal monitoring report, has not been updated for months. If anyone has further tips to avoid a future potential jobs backlog problem, I would be happy to make further changes to the crontab etc.