After installing CEON URI the session is wiped when a customer tries to log in - meaning, login is impossible. I traced this down to init_sessions.php in includes/init_inludes/overrides. The only thing that file does is to force the cookie path to be set to root "/" (Zen Cart resides in "/purchase/" in my case). Apparently that doesn't work, but I have not been able to identify why. What are common reasons that setting cookie path to root fails?