I enabled my apache with SSL recently.. Had to change many files.
And once I managed to get SSL working, I noticed my PHP configuration was messed up..
I had no idea what to do.
My PHP files were shown as Plain text.
I searched and searched on the web, when suddenly I figured out the problem without finding it online.. which is exactly why I maintain this blog.
The solution is SO SIMPLE it's simply annoying..
Check your conf/mime.types file and make sure you see the lines
application/x-httpd-php php application/x-httpd-php-source phps
That solved the problem to me..
Please comment me if it didn't help you - I would love to solve your problems as well.