I'm not a huge fan of having to symlink every site to that new php5 directory... but I'll deal.
Problem, when I get to the part of modifying the htaccess file, I made it only be the following
AddHandler php5-fastcgi .php
Action php5-fastcgi php5/php5-wrapper.fcgi
(changed /php5/php5-wrapper.fcgi to php5/...)
400 Bad Request
Your browser sent a request that this server could not understand.
This happened with other htaccess lines for rewrite, so I tried it with just the cgi stuff and it still does it.