What is causing Drupal to return a 404 HTTP header, but correctly return the page? I have a Drupal 6 site that is correctly returning site content (like the home page), but if you look at the response headers every page has a 404 header, instead of a 200.

Things I've tried:


Rebuilt the node access table (/admin/content/node-settings/rebuild)
Cleared the cache
Run update.php


Do you have any idea on what might be causing this?
Are you using clean urls?

It is possible that Drupal is called through the 404 error handler which results in the 404 header.

Make sure your .htaccess configuration is correct and that mod_rewrite is enabled and you're allowed to override the relevant settings.