I'm running into a strange issue that I've never seen before: visitors to a Wordpress-powered website occasionally see the contents of Wordpress's automatically-generated robots.txt instead of the page they're trying to visit.
Specifically, all the visitor sees is:
User-agent: * Disallow: /wp-admin/ Disallow: /wp-includes/
A refresh of the page allows them to view the actual page.
The issue seems to be browser- and location-independent, and doesn't seem to have any consistent cause - it happens sporadically without notice. I've ruled out any plugins causing the issue, and at this point I'm not entirely sure whether it's an issue with Wordpress (3.5.1) or the web server itself.
Has anyone ever experienced this, or have any idea what might be the cause?