Exactly the same problem I had last July. This time, the missing post -- completed, saved, and posted yesterday! -- was at http://raywoodcockbio.wordpress.com/2014/01/23/. Last July, the discussion thread was at en.forums.wordpress.com/topic/wordpress-ate-my-work-no-revisions-listed. How is it not possible for WordPress to keep an overnight backup?
The blog I need help with is raywoodcock.wordpress.com.