Apache/2.2.14 (Ubuntu) - 2.3.7/silverstripe_version
In sapphire/main.php there is a comment that reads:
* It's important that requests that point directly to a file aren't rewritten; otherwise, visitors * won't be able to download any CSS, JS, image files, or other downloads. * * On Apache, RewriteEngine can be used to do this. * * @package sapphire * @subpackage core * @see Director::direct()
This came about because I recreated my site from an old backup after moving house and server. For some reason the original index.php was missing from all my backups except one.
I am not sure if the index.php I eventually did find is the right one for my Silverstripe version (version: 2.3.7).