There is a difference between remembering the name and password in the Password Manager and a "remember me" check box on a web page.<br /> The latter usually involves the creation of a special "remember me" cookie that is stored on your computer and that is send to the server.<br /> If that "remember me" cookie is removed or gets corrupted or is not send to the server then the server won't remember you and you need to sign in once again.<br /> * http://kb.mozillazine.org/Websites_report_cookies_are_disabled (Other Solutions)<br /> Create an allow cookie exception (Tools > Options > Privacy > Cookies: Exceptions) to keep such a cookie, especially for secure websites and if cookies expire when Firefox is closed. Make sure that you do not run Firefox in Private Browsing mode. * https://support.mozilla.com/kb/Private+Browsing * In [[Private Browsing]] mode all cookies are session cookies that expire if that session is ended, so websites won't remember you. * In [[Private Browsing]] mode Firefox won't fill names and passwords automatically and won't offer to store new passwords.