In my blog, 1neidea.com/blog, I drafted a post around a month ago, and then finished and tried posting on Sept4, but had trouble getting the published/scheduled settings to resolve (I wanted it published, but it kept saving back to scheduled, even when I tried to use a timestamp that was easily weeks ago). So I decided to turn in for the night and revisit it the next day. Now when I check my manage post page, the latest post is missing entirely. Not only that, when I check the tabs ("All Posts". "Published", "Scheduled" "Drafts") they don't add up. For instance, the All Posts indicates nothing at all (no digit present) but it shows only my single (legitimate) draft post, the Published Posts indicates 8 (which is correct number), Scheduled indicates 1 (but no post appears in that tab list at all), and Drafts indicates 2 (yet only one post is listed in that tab).
Thankfully, I can almost replicate verbatim the post that seems to be missing, as it happened to be rather short. But the real problem is the incorrect tab indicators. I am using the WordPress theme Atahualpa 2.01 by BFA Webdesign - I even tried loading a different theme in case that was the concern, but the problems still persist. I doubt it really makes sense to try another post or mess with the existing ones until I figure out what the heck happened.
(EDIT: the WordPress version is 2.5.1, not 2.6.1 - sorry)