It sounds like you have cookies turned off. When you login perlmonks trys to story a user cookie and when you access the site it checks for the precense of this cookie to determine if you should be logged in or not. When you hit the login box, if it validates your password it tries to store a cookie but it has no way of knowing if storing a cookie suceeds. So it thinks it logged you in properly but when you hit another page you have no login cookie to authorize.