Rich,
I just tested logging out and I was left on the same page. However, I noticed that you're not even using the SCLogin module for the logout button. If that's not working for you, it may not be an issues with our module but with the Kunena login module you're using. When you try to logout, where are you redirected?
Finally, for Autotune, I don't know what the change was, but we're constantly updating Autotune to improve our detection and recommendations. I don't know what may have changed in our recommendations for your site offhand though.
I hope that helps, but keep me posted on what you find.
Thanks,
Alex