I suddenly noticed the admin’s post editing page doesn’t show all the posts. It stupidly is affected by the number of posts shown on the blog’s index page which certainly isn’t the way it should be.
Well, I tried his idea (copy-pasting a code snippet from post.php to edit.php to reset some variables) but I couldn’t get it working. So, I made an “unprofessional” patch.
I haven’t had more than 50 posts per month (that’s how the posts are categorized) so I added a variable to show 50 posts “per page” (there aren’t any pages, really). This is at the very top of edit.php:
$title = __('Posts');
As the forum posts suggested, you might have to do something about the edit-comments.php too, but I have exactly 10 comments so far so I don’t know if all of the comments will show.