Taking an existing WP site (created by someone else) and making a local copy for development. After I copy all the files over and import the sql database, all the posts show as "(no title)", with no time/date/author/tags/etc. Pages are fine.
The data seems fine in the DB. Problem exists if I import the DB into a clean wordpress filesystem, so it's probably not any changes made to core on the site. I've exported/imported the DB a half dozen different ways to make sure it's not something weird phpmyadmin is doing.