Debugging WP-Cron when it's not working, even manually

Hi

The WP-Cron implementation on my site doesn’t seem to be working at all. I’ve tried disabling it and calling it from a cron job every 5 mins, but things still aren’t firing off.

I’ve installed Cron View plugin which shows that things are in the Cron list, but the actual events it shows doesn’t tally up with the list of items in the cron list. For example our backup is set to run every 2 days but only shows in the event list once in the last month.

Before we went to manual we had it set to automatic, and even with many thousands of users a day, it wasn’t firing at all.

Is there anywhere to go from here?

Olly