Let me remove the last sentence there: I've gone into Windows, Start, and right-clicked on Documents. It has the proper address. So Firefox isn't inheriting its mistake; it's insisting on it!

You seem to be having a ton of issues with Firefox, and I can feel your pain. I think you should just do a clean reinstall

Certain Firefox problems can be solved by performing a Clean reinstall. This means you remove Firefox program files and then reinstall Firefox. Please follow these steps:

Note: You might want to print these steps or view them in another browser.

1. Download the latest Desktop version of Firefox from http://www.mozilla.org and save the setup file to your computer.
2. After the download finishes, close all Firefox windows (click Exit from the Firefox or File menu).
3. Delete the Firefox installation folder, which is located in one of these locations, by default:
   • Windows:
     • C:\Program Files\Mozilla Firefox
     • C:\Program Files (x86)\Mozilla Firefox
   • Mac: Delete Firefox from the Applications folder.
   • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
4. Now, go ahead and reinstall Firefox:
   1. Double-click the downloaded installation file and go through the steps of the installation wizard.
   2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

More information about reinstalling Firefox can be found here.

WARNING: Do not run Firefox's uninstaller or use a third party remover as part of this process, because that could permanently delete your Firefox data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. These cannot be recovered unless they have been backed up to an external device!

Please report back to see if this helped you!

Thank you.

Thanks. I'm afraid I'll stop short of that for several reasons. (1) It seems too weird to blame it on a corrupt installation, as (a) it was fine except for not shutting down properly after v29, a clear bug, and (b) the rest of the problems, like this one arose precisely from Rest. In other words, you're saying that Mozilla's own solution caused the problem. Hmmm.

(2) It'd take forever, recovering all my data etc. If I'm going to start over on a buggy program, why not get a working program? I'd miss Firefox after it's entire existence, as I go back to Netscape, but darn.

(3) I have a lot of my files backed up in a zip file. I just used them to overwrite the ones in my profile. That recovered a lot of setting issues, except actually for this one, but . . . .

(4) Let me give you more data, hoping it will help. I've toyed around. If I browse to Downloads, it again dupes: C:\Users\JohnH\Downloads\Downloads. If I go to the parent, it even dupes JohnH. If I go back Documents, it dupes that. So there's a consistent pattern here to debug.

Perhaps a solution? While I couldn't edit manually the address in Options (only select a folder), I did so in about:config. We'll see what happens.

These add-ons can help you to restore your system;

FEBE (Firefox Environment Backup Extension) {web link} FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backup of files that you choose. Firefox Environment Backup Extension Home Page {web link}

OPIE {web link} Import/Export extension preferences

A corrupt file could happen at any time for thousands of reasons. Some programs can detect that a file was damaged, and try to repair. Others can't or don't. By doing a clean install, and damaged file(s) will be replaced.

Did you do a disk and file system check with the chkdsk.exe program?

If you run the chkdsk.exe program from a cmd.exe Command window then you can read the response from the chkdsk.exe program. Open a cmd.exe window: Start > Run: cmd.exe <press Enter> At the command prompt (>) type or Copy&Paste: chkdsk.exe /f /r <press Enter> (put a space before /f and /r) If you get something like: Would you like to schedule this volume to be checked the next time the system restarts? y/n then answer the question with "Y" and close all programs and reboot the computer.