I was having problems with certain functions in Quick Cache, and realized it's due to my wp-cron.php not executing (though I do receive regular WP/plugin/theme update notifications, and these are triggered by cron, correct?). I've installed Cron GUI to monitor my WP cron jobs, and the only way I get them to run is to manually invoke wp-cron.php. I've checked all the obvious things, like whether cron is disabled in wp-config.php (it isn't). I also installed WP-Cron Control to override the default wp-cron, and my logs say I got it running successfully on my Ubuntu server but it too failed to process the WP cron queue. (My Ubuntu server cron processes are working fine, btw.) I even tried a workaround for v2.9 just in case, but it didn't help.
I'm out of ideas, and would sure appreciate some guidance.