massive Issue with Caching and ModExpire on php Files
php,.htaccess,caching,mod-expires
To prevent php files from caching try to remove ExpiresByType application/xhtml-xml, which is for PHP. IMHO you can also remove FilesMatch for PHP files....
Apache still load from cache even disable mod_expires
When you send Expires header to browser, it will cache your response and only check for newer version after the expiration date has passed. Since browser won't check for newer version, changing your server settings won't affect browser's cached data. If you made some mistake in your script or there...