This problem usually indicates that your cookies are being cleared between sessions. By default, Firefox allows cookies to persist for as long as the site requests. You have the option to globally switch to session-only cookies, or to manage cookies on a site-by-site basis. Firefox also has a feature to remove cookies at shutdown. (In private browsing sessions, all cookies are retained only for the duration of the private session.) Based on your More System Details, it does not appear that you have a global session-only rule, nor do you have Firefox set to clear cookies on shutdown. You could double-check in the Options dialog. orange Firefox button (or Tools menu) > Options > Privacy If you have the drop-down set to "Firefox will: Use custom settings for history" you can see the cookie settings and whether anything is set for cleansing at shutdown. Two other ways cookies might be cleared are: * Add-ons that target cookies (your do not seem related to cookies) * External security / privacy / cleaning software Could it be something running outside of Firefox?