If I have all three showing (in header, in page, and in sidebar), the page and sidebar logins work, but the header still shows the message as if I haven’t entered anything.
Also noticed that the redirect after login is not working. It’s just reloading the same page.
Also the registration popup only work when clicking on the first instance of login form (header if all three, page if only page and sidebar). Other register links like to actual WP registration page.
Also the registration popup is always giving the same message of:
Please supply your username and password.
Hope that helps narrow down the issue!