I have a custom login page. I don't know if this is reatled to the problem but when I want to login with Chrome auto filling the login and password areas, Wordpress gives error: Password field can't be empty. Anyway, I type the password and login. Everything works fine. But when I click to see the web page in action, I am logged out and have to login again. SHould I disable login page caching ? Or is the problem related to plugin WPS Hide Login ?