(1) One of the unfortunate features of the Library dialog is that it doesn't indicate which folder a particular bookmark is in... but you are using the "Show Parent Folder" extension, so you do have some additional information. But I think you still can't see the full path.

If you have ever imported bookmarks from another browser, you might have a duplicate copy in a folder named something like Imported Bookmarks or Bookmarks Imported from some other browser. That might not be obvious from the Library dialog even with the additional column of information.

Here's a thought. Use the Export to HTML feature, and then open that file as a webpage in Firefox and use the find in page feature to see whether you have an extra copy of the Shell folder and cross-reference that back to the Bookmarks Menu so you can remove the duplicate.

This article covers the exporting part: Export Firefox bookmarks to an HTML file to back up or transfer bookmarks.

(2) Do you use Firefox Sync? If you sync between Windows and Android, I think it might be possible to get some duplication. I haven't read past threads on that closely.

Hey, one of the reviews here says you can turn on full bookmark hierarchy viewing in the extension's options: https://addons.mozilla.org/en-US/fire.../show-parent-folder/. Then you wouldn't have to export to see that information. Does it work?

Don't recall importing Bookmarks into Firefox from IE when I switched seven and a half years ago. I would estimate that >95% of my Bookmarks are new since then ... so wouldn't that be immaterial?

Duplicate search "results" date from initial use in 2005 until about Mar. 15 (Ides of March), 2013. This means the "results" list is about twice as long as necessary, hindering use of Search.

I don't use Firefox Sync and don't have an Android.

Re "Hey, one of the reviews here says you can turn on full bookmark hierarchy viewing in the extension's options: https://addons.mozilla.org/en-US/fire.../show-parent-folder/. Then you wouldn't have to export to see that information. Does it work?"

YES!!!! MOST EXCELLENT. That's will be very helpful. Thanks so much!!

In my case the bookmarks ARE actually duplicated. I have verified this by exporting them and analyzing the HTML. The entire "All Bookmarks" hierarchy had somehow been copied into a random location of my bookmark tree. That is why all bookmarks except recent ones are being found twice. It looked like this:

- All Bookmarks
  + Bookmarks Toolbar
  + Bookmarks Menu
     + MY_FOLDER_A
     + MY_FOLDER_B
     - MY_FOLDER_C
       MY_NESTED_FOLDER_A
         - All Bookmarks
            .... older state fully duplicated!!!

I have deleted the nested copy of "All Bookmarks" and it looks OK now. Either I have made that copy by mistake (which I highly doubt) or a bug caused it.

Good to hear that you don't use Firefox Sync (I use it). That would have been a premier candidate for causing a problem like this. (My bad bookmarks were replicated to all computers linked with Sync).

The copy of "All Bookmarks" must have been made within the past few months, but I could not determine exactly when. The copies have the same ADD_DATE and LAST_MODIFIED timestamp in the HTML file.

Such issues can be caused by a corrupted places.sqlite file.

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

Several days after posting my problem, I discovered that it was exactly as StaticNoiseLog describes (Posted Today at 9:59 AM). I could (and should) have written a few weeks ago what SNL said, "The entire "All Bookmarks" hierarchy had somehow been copied into a random location of my bookmark tree. That is why all bookmarks except recent ones are being found twice." "I have deleted the nested copy of "All Bookmarks" and it looks OK now." In my case, I've give myself >50% chance of being the unintentional culprit rather than it being a bug, but ... Thanks to cor-el for an astute observation.

Just for the records: If one has to dive into the subject of corrupted places.sqlite databases, the following might help:

• Locate "places.sqlite" with Help, Troubleshooting Information, Show Folder
• Close Firefox.
• Copy places.sqlite to another place.
• Use DbVisualizer (free edition available) or a similar tool to open the places.sqlite DB.

The following SQL statement will list the duplicate URLs (be they stored by mistake or through a bug):

select *
  from moz_places
 where id in
      (select fk
         from moz_bookmarks b1
        where rowid <> (
              select max(rowid)
                from moz_bookmarks b2
               where b1.fk = b2.fk)
               order by fk)