one thing to consider.
when you browse <b>
http://tfproject.org</b>, you receive a cookie
when you browse <b>
http://www.trpfoject.org</b>, you receive another cookie.
when you log out of one, it may still see the other's cookie.
browse from
http://tfproject.org (no www) as much as possible. if you log out of that incarnation and still find yourself logged in, hit the www site and try it again, or vice versa.
it's an odd problem, but it happens.