If you happened to mis-type your username/password when trying to login to a website before, then you must feel the frustration when Firefox keeps remembering your little mistake forever. I just found out how you can break free and have Firefox behave!
You can delete any username/password combination that you don’t want Firefox to remember. This is helpful because, if you typed a wrong info the first time, then typed the right one, Firefox will never auto-type your login info for that page again!
To end up this mess:
* in Firefox text menu, click at: Tools > Options > Privacy > Saved Passwords > View saved passwords
* scroll down to the web page that you want, which has the wrong username and/or password. Select it, then click at the ‘Remove’ button. If you need to see your password in that list, click ‘View passwords’.
Now that you deleted your wrong login info, the next time you visit that page, your correct login info will be there, nice and automatically typed for you. Now you can live happily ever after!