Strange things are afoot.
Funnily enough, I managed to break almost every part of the site requiring authentication when I started bringing in the speed improvements. For some reason the php.ini setting session.save_path got reverted to some value that wasn't writable by the web server process running on my privileges and prevented me from doing anything when logged in.(Instead the session just ended on every page load and I had to relogin.)
To make things much harder to debug, my development server environment was able to write to it's own session.save_path and everything worked there as expected.
Now I just have to fix a couple of links misbehaving on my registered user interface.Pallokorva Apache Php