After upgrade to WordPress 2.7 I noticed that a Schedule Post option is not working anymore. I can still schedule a post for particular time, but when WordPress should publish the post it gave me just ‘Missed Schedule’ notification. WordPress 2.7.1 update has not fixed this error.

The problem occurred apparently because of changes in WordPress Cron, not giving sufficient time at certain servers in order to take out the publication of the post.

To fix Missed Schedule error you need to replace two files in WordPress installation folder wp-cron.php (located in the WordPress root) and cron.php (located in the ‘wp-includes’ folder) with older versions of these files from WordPress 2.6.5

After you overwrite these two files with older versions next scheduled post should be published by WordPress without any problem.