Since using sync I now have duplicate bookmarks, but if I delete one bookmark it deletes it's duplicate too, how do I get rid of this second set of bookmarks?

Problems with bookmarks and history not working properly can be caused by a corrupted places.sqlite database 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

You can try to check and repair the places database with this extension:

• https://addons.mozilla.org/firefox/addon/places-maintenance/

My problem isn't that the bookmarks don't work, the problem is that when I open my bookmarks tab instead of one bookmarks menu folder I have 2,. Deleting a bookmark from one folder automatically deletes it from the other....so it's not as simple as just deleting the duplicates, also the duplicate bookmarks menu folder can't be deleted even when empty. All of this is on a fresh install of firefox, the very first thing I did after installing it was to sync with my laptop to get all my bookmarks.

The places.sqlite database may still be corrupted if the same bookmarks show in different locations.