On my site scheduled posts are being missed and newsletters aren't being sent out on time. If I visit wp-cron.php?doing_cron manually, then the scheduled posts will be posted okay.
In my server logs I see entries like
"POST /wp-cron.php?doing_wp_cron=1358425422.1426320075988769531250 HTTP/1.0" 200 - "-" "WordPress/3.5; http://www.domain.com"
so it appears that cron is being called automatically.
I have tried following the steps suggested here: http://wordpress.stackexchange.com/questions/13625/how-to-debug-wordpress-cron-wp-schedule-event
I have cleared up most of the errors that were appearing in the debug.log, apart from one related to get_theme_data being deprecated. But still cron is not working automatically.
I have searched my project for the string 'DISABLE_WP_CRON' (in case it was defined in a plugin or something strange), but it is only mentioned in cron.php where it is checked to see if it is defined.
The cron view plugin just lists the cron tasks and doesn't show why cron won't work automatically.
So cron works manually, but not automatically, and I can't find out why it does not work automatically. Does anyone have any advice on how I can debug why it is not working automatically?