A few months ago I had a phpbb forum with ajax chat and it worked fine.
However, I shut it down.
Now 2 months later I reopened it and reinstalled AJAX Chat but it won't work.
Basically, it does this:
* Go to the chat
* Will be greeted with login box
* If you don't enter your credentials, you will be logged in as a guest.
* If you do, it will show "You have successfully logged in." and when you return to the previous page you are logged in for a split second but then it will log you out again.
If you want to see for yourself, here it is:
http://nookls.org/forum