Won't let members logout?

Technical Details

Forum version : #phpBB2
Position : Founder
Concerned browser(s) : Google Chrome
Who the problem concerns : All members
When the problem appeared : After inserting the popup login box.
Forum link : http://www.gasrforum.com/

Description of problem

So I noticed this problem a couple days after inserting the custom pop up login created by @Ange Tuteur Moderators on our forum switch accounts quite a bit (we have accounts created to be a "message box" for certain things) and for some reason it won't let us logout. It doesn't matter if we check "remember me" or not. We also tried disabling the custom popup box with no success and even when we do without it, it still happens. We also have edited the custom toolbar quite a bit.

Do you mean that they do not see the log out button?

No the logout button is there. We use the one on the forumotion toolbar, however, whenever you try to logout it keeps you logged in??

Like for example, I would be logging out my account and trying to log in another and it would just take me back to my previous account.