Maybe there is a problem with the files that store the passwords.

See http://kb.mozillazine.org/Password_Manager (Troubleshooting)

The link you offer is the guide I am pointing out is useless. (in my case, because that is what I followed when the problem first arose)

I have done everything on that list, and I am still not offered the option of saving passwords.

Are you suggesting that I backup my profile, uninstall Firefox (again) and restore my profile to the new install of Firefox? Believe me, that doesn't help.

What file stores the passwords? If it's become corrupt then backing it up and restoring it is simply restoring the corruption... what I need to know is how to fix it, not how to reproduce it... unless you want me to send you a backup of my stored passwords. (I don't think so. lol)

If I could manually add a username and password to the list in the stored password manager that would be a sufficient solution for me, but I can only remove them from there.

The "Troubleshooting" section in the http://kb.mozillazine.org/Password_Manager#Troubleshooting article will tell you exactly which files are used to store the password and where you can find them.

It's Firefox 3.6.6

I have "signons.sqlite", "signons2.txt" and "signons3.txt" as well as the "key3.db".

I can back them up... and restore them, but I can't read or edit them. I don't WANT to back them up, or restore them. I want to add usernames and passwords to them.

Firefox is still offering to fill in my username and passwords for sites it has stored (though, if I change my password it will not update its list), but it isnt' offering to store any new ones, or update existing ones.

I guess I should follow the "incomplete" instruction

"If you can't add new passwords but still see your old passwords in the Password Manager window then use the Password Exporter extension to export your current passwords and delete key3.db and delete or rename signons.sqlite and all signons#.txt files (e.g. signons3.txt and signons2.txt) in the Profile folder - Firefox. You can also do that if you lost your Master password and the suggestions in the Master password article didn't work. You need to set a new Master password after deleting the file key3.db."

I call it "incomplete" because it doesn't tell me how to re-import those passwords, and if I use FEBE or MozBackup, it re-imports the problem as well.

I now realise that I haven't tried the "Password Exporter" yet... so I'll do that, and see how it goes.

---EDIT--- Okay... I lost 4 of my 50 passwords. And it still isn't remembering new passwords. :(

Similar, but different problem: I deleted the password for one particular site because I had changed it and the "Change Password" and "Remember Password" options weren't working. Now I don't even get offered the option. I am NOT in private browsing mode and have the latest update running. I've got all the other Privacy and Security options set as recommended. This is for a site I use often which has a lengthy numeric userID that I cannot change, so a remembered password would be nice. Other sites still trigger the option to remember a new password, but Firefox seems to be holding a grudge against the site that I cleared.

IDK that this will help, but my problem turned out to be that I had "Saved Passwords" ticked to be cleared when Firefox closes.

Now, I usually clear /almost/ everything when I close FF. I don't like it to remember the history of URLs I've visited and I want cookies and such to be session only for all but a few very specific sites... just to reduce the breadcrumb trail, and because I can copy a URL to my clipboard, close FF and re-open to reset any settings I've made on a site. (unless they are stored server-side) But it was only after a recent 3.5.x update that ALL passwords stopped being stored, or even asked to be remembered. (now running at 3.6.6, and I usually do accept any and all stable updates offered, and my settings have been running since around FF 1.7 when I started transferring more than just my bookmarks from one version to another.)

I wonder if it isn't a new, or moved option that has picked up it's tick from something similar, but operating slightly differently.

Also, I believe that when I tried ticking "Automatically start Firefox in a private browsing session" doesn't show that you are using private browsing, as it's recommended you check... you /have/ to look for that tick. (In Options -> Privacy)

You are in Private Browsing mode if you see "Tools > Stop Private Browsing", possibly grayed if you start Firefox automatically in Private Browsing mode.