I have apache 2.2.4 and i try to get SilverStripe 2.2 working.
But after installing it sucessfully, i have a problem with mod rewrite
it's working but instead of execute sapphire/main.php on the server.
the browser prompt to download it.

So i get all the php code of main.php on the client!

mod_rewrite is working but seems like after it php was disabled and prompt to download the file

but php is working too because http://localhost/install.php it still working.

AllowOverride ALL is set in the folder of web server.

I try many thing but i cant get it working.

Some idea?

There must be something wrong with your php settings, I never had similar problems