I have a WordPress site that runs fine, but there's a strange behaviour: one a reader loads the page, the site shows a "cached" version of the site, with the same news and comment numbers that the reader viewed when he visited the site last time.
So every user has to reload the page (Ctrl+F5, Cmd+R) in order to get the "real", and updated homepage.
I don't know why this is happening. At the moment I'm not using any cache plugin, and my server is running Nginx+MySQL+PHP-FPM on a Ubuntu 10.04 LTS Linux VPS. Is there something I must change on the nginx config files, maybe?