Hi Guy, Firefox may save usernames and email addresses in multiple places. These include: * Saved Logins (menu button > Passwords) - it sounds like you already cleared the old login from this one * Form History * Address form fill For Form history, you usually can start typing text to show saved matches, then press the down arrow key, then the Delete (Del) key to remove the match from form history. More info: [[Control whether Firefox automatically fills in forms]]. Address form fill may or may not be available for email address fields from time to time. For more info on cleaning up this data, see: [[Automatically fill in your address on web forms]]. Can you find/resolve the problem in any of those areas? Oh, finally, I should mention that some sites store a username history in a cookie or local storage. You can clear cookies and local storage entries set by the site this way: While viewing a page on the site, click the lock icon at the left end of the address bar. After a moment, a "Clear Cookies and Site Data" button should appear at the bottom. Go ahead and click that. Firefox will ask you to confirm; go ahead and confirm. Hopefully it was one of those things.