Strange. Would everyone who is having this problem mind answering the info on post #9 in this thread? The more info I get, the easier it will be to troubleshoot.
This only happens to me if I click on a link to some other post in the forum. I do tab browsing, so I always have the one screen at the homepage. If I refresh that page I am still logged in.
Try one thing... Make www.gotitans.com the page you start on. I think I may have a problem where those who enter at gotitans.com are getting logged out once they hit a www.gotitans.com page.