My blog had the following custom permalink structure: /%postname%+%post_id%. As such, this blog's urls looked like this: http://mydomain.com/blog-directory/post-title+post-id
Between the 18th and 19th of November 2008 3 blog post and 1 blog page were added. The permalink structure worked as expected.
Another blog post was added December 1, 2008 using the same custom permalink structure. But this post does not show up after being published. The blog displays this message "Error 404 - Not Found".
To the best of my knowledge, nothing was changed on the blog. Plus, the permalink structure still works for previous blog post. Only new ones are affected.
This is WordPress v2.51 running on Apache and Linux. Any changes I make to the permalink structure work for the posts written between the 18th and 19th of November; but do not work for newer posts written in December. In fact, in order for new post to show up one of WordPress default permalink structures most be used or a custom permalinkf using a dash as a separator.
Why want the custom permalinks work for new posts?