I think I did a stupid thing. I upgraded my Squeeze box to PHP 5.4.40 and now none of my sites are working. I am getting an internal server error 500.
I tried adding:
AddHandler application/x-httpd-php5 .php AddHandler application/x-httpd-php .php4
to a sites .htaccess, but then the site just downloads the index page instead of displaying.
Has anyone come across this before? I am at a loss and google isn't much help. Right now I have about 15 sites with upset admins :/