Extract from debug log. The post mentioned is 99.95% likely not to be a visitor request, so I assume it is being preloaded.
14:50:49 /wp-cron.php?doing_wp_cron=1339339835 wp_cron_preload_cache: fetched http://www.mysite.com/how-to-increase-the-light-in-your-home-with-a-paint-that-reflects-up-to-twice-the-light-2008/
14:50:50 /wp-cron.php?doing_wp_cron=1339339835 supercache dir: /home/root/public_html/wp-content/cache/supercache/www.mysite.com/not-feeling-very-well-tonight-2015/
14:50:50 /not-feeling-very-well-tonight-2015/ mobile browser detected: WordPress/3.3.2; http://www.mysite.com
14:50:50 /not-feeling-very-well-tonight-2015/ supercache dir: /home/root/public_html/wp-content/cache/supercache/www.mysite.com/not-feeling-very-well-tonight-2015/
14:50:50 /not-feeling-very-well-tonight-2015/ No wp-cache file exists. Must generate a new one.
14:50:51 /not-feeling-very-well-tonight-2015/ In WP Cache Phase 2
14:50:51 /not-feeling-very-well-tonight-2015/ Setting up WordPress actions
14:50:51 /not-feeling-very-well-tonight-2015/ Created output buffer
14:50:51 /not-feeling-very-well-tonight-2015/ Output buffer callback
14:50:51 /not-feeling-very-well-tonight-2015/ Anonymous user detected. Only creating Supercache file.
14:50:51 /not-feeling-very-well-tonight-2015/ mobile browser detected: WordPress/3.3.2; http://www.mysite.com
14:50:51 /not-feeling-very-well-tonight-2015/ Gzipping buffer.
14:50:51 /not-feeling-very-well-tonight-2015/ Writing non-gzipped buffer to supercache file.
14:50:51 /not-feeling-very-well-tonight-2015/ Writing gzipped buffer to supercache file.
14:50:51 /not-feeling-very-well-tonight-2015/ mobile browser detected: WordPress/3.3.2; http://www.mysite.com
14:50:51 /not-feeling-very-well-tonight-2015/ Renamed temp supercache file to /home/root/public_html/wp-content/cache/supercache/www.mysite.com/not-feeling-very-well-tonight-2015/index-mobile.html
14:50:51 /not-feeling-very-well-tonight-2015/ Renamed temp supercache gz file to /home/root/public_html/wp-content/cache/supercache/www.mysite.com/not-feeling-very-well-tonight-2015/index-mobile.html.gz
14:50:51 /not-feeling-very-well-tonight-2015/ Sending buffer to browser
14:50:51 /not-feeling-very-well-tonight-2015/ wp_cache_shutdown_callback: collecting meta data.
14:50:51 /not-feeling-very-well-tonight-2015/ Did not write meta file: wp-cache-ab7f9785e8c38ee97709a9246c49f99f.meta *1* *1* *1*
14:50:51 /wp-cron.php?doing_wp_cron=1339339835 wp_cron_preload_cache: fetched http://www.mysite.com/not-feeling-very-well-tonight-2015/
14:50:52 /wp-cron.php?doing_wp_cron=1339339835 supercache dir: /home/root/public_html/wp-content/cache/supercache/www.mysite.com/superb-food-from-other-great-blogs-chef-at-large-sids-meat-and-oatmeal-stew-2021/
I am using a theme from Elegant Themes, with their ET Mobile plugin also.
While I probably could disable that and do a preload, it would be back in place for the scheduled refresh.