On my site I have 3 Q2A installations sharing the same user base. When I log in to any of the 3 sections, it logs me in to all sections. However, when I log out of either of the 3 sections, it only logs me out of that section! I stay logged in on the other 2. This happens on IE, Firefox and Chrome so it's not just one browser.
On the main site I have this in the config:
And on the meta site I have:
I checked the cookies. When I am logged in I have 2 cookies: qa_session and qa_noticed. When I log out of one section the qa_session cookie is gone, qa_noticed is still there. There is also a PHPSESSID cookie which is always present. The only other cookies are Google Analytics ones (__utma etc).
Why is this happening? If the qa_session cookie is gone I would assume there is no way for Q2A to know which user is logged in.