Colorbox User Login Block does not work

I am Colorbox Module 7.x-1.0-beta2. When I choose the User Login Block option for Login form to use under Colorbox configuration, and try to login, I see the login block displayed in the colorbox popup. However, after entering the username and password, when I hit the Login button, the site does not log me in and displays the login page (user/login?destination=user). Incidently, if I choose User Login option for Login form to use, the colorbox accepts the username and password correctly and logs me in.