You can set the auto-fill prefs to false on the about:config page.

• signon.autofillForms = false
• signon.autofillForms.htpp = false

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config

Thanks but this did not solve the problem. Setting both lines as you recommended removed my password but not my email address, leaving the same conditions to my problem.

What aspects of history are you clearing that removes the data successfully? For example, the "Clear Recent History" dialog lists these categories of data (you may need to use the Details button to see them):

• Browsing & Download History -- should not have any effect
• Form & Search History -- may be important
• Cookies -- may be important (if Facebook uses the cookie data to prefill the username, it should never prefill the password)
• Cache -- may be important -- see test below
• Active Logins -- not applicable to logins through web forms
• Offline Website Data -- does not sound relevant
• Site Preferences -- don't clear this (covers site-specific permissions such as which can set or not set cookies, show popup windows, access location, etc.)

Firefox preserves some form data when pages are reloaded, if the server has not sent strict enough instructions not to do so. Reload the page bypassing the cache to view the form as sent by the site without anything filled in from the cache. Either:

• Hold the Shift key when clicking the reload button in the address bar
• Ctrl+Shift+r (Mac: Command+Shift+r)

Does the email address still appear in the box, or in a drop-down below the box?

No big help, I'm afraid, but posting it anyway,   just in case :
https://www.facebook.com/help/community/question/?id=826683304076223

You may once have stored this username as saved form data. Try to delete all the text in the name field and then start typing the first letter or double-click the name field to see if that gives you a suggestion in the drop-down list. Then you can highlight this item in the drop-down list and press the Delete hey to delete this saved data.

Thank you. I maintain my settings to clear form and search history, cookies and cache.

I can delete the email address and password independently and when I do, I get the drop down menu of Facebook passwords. Doing so is an extra step that I have not had to do previously.

You will probably already do this,   but just to make sure : The moment you want to login to your Facebook account, at the Log In page, there’s a small checkbox that says : "Keep me logged in". Make sure this box is unchecked. Then, log in as usual. With this on, you will be asked for your email and password every time you launch Facebook.

Also see : http://www.hongkiat.com/blog/facebook-account-security/

charlesleggett said

I can delete the email address and password independently and when I do, I get the drop down menu of Facebook passwords. Doing so is an extra step that I have not had to do previously.

Is it possible you had Firefox save your Facebook login? You can check for and clear that on the Options page:

Windows: "3-bar" menu button (or Tools menu) > Options Mac: "3-bar" menu button (or Firefox menu) > Preferences

In the left column, click Security. Then on the right side, find the "Saved Logins" button.