very strange problem just started happening on a site I'm developing. Everything was working fine and suddenly all pages and posts route to the same post (single.php) page. I mean everything, archive, page etc except for the homepage. I have no idea what might have triggered this as there are several of us populating the site with content to get ready for launch.
I'm using a custom permalinks structure but even going back to default results in the same thing. The URL is reading correctly but it will only show this one post. Deleting the post results in everything going to a 404 page.
Is something in the database broken? Only using a couple of plugins and nothing that deals with the permalinks.
Any ideas, I've never seen this before.