When you open the ACP, click 'view your forums' and click logout in the "body" frame, then it'll show that you are logged out. The strange thing is, the ACP sideframe still remains. I was able to modify my forums setting that way. Upon opening a new browser window and pointing it to the forums main page (the ACP settings were still open in another window) it showed me as a guest.
-David
I believe 'view your forums' should be target _blank instead of inside the frame.
there is no relation between loging out OR In to the Board and to the Admin CP.
For example you can login to you board, click admin cp and it askes you to login again.
No in your case you have logged out from the board it-self and not the Admin CP.
Many regards
The Admin CP and the front end are on two different authentication systems, so if you're on a public computer and you access your ACP and front end you should make sure you logout of both.