I am not sure there is anything to synchronise. I get the impression the sidebar merely displays a subset of the information available. Have you tried scrolling to make sure you are not missing items lowerdown, and have you tried clicking the [+] boxes to expand branches of the sidebar.

Are you saying you can for instance make changes successfully in bookmarks listing of the sidebar, adding new bookmarks, and those new bookmarks will survive a restart of firefox and persist but can not then be found in the bookmarks library. Have you tried the search function in the library, maybe the bookmarks are in another folder, and you are duplicating folder names.

I would suggest you see what happens if you use Diagnose Firefox issues using Troubleshoot Mode possibly one of your addons is interfering with what happens. (I have not tried using the add on IE Tab, but I note it is listed in your system details, is that interfering or even creating a set of bookmarks for IE use)

As for most problems with Firefox bookmarks a good starting point for solving problems is the article lost bookmarks

Found something!! Thanks to your idea to search the bookmarks library.

Looks like I accidentally got a copy of the Bookmarks root "All bookmarks" into a deep folder of bookmarks.

The strange thing is that the Bookmarks-sidebar holds it has the "real" bookmarks root!

This can be a problem with the file places.sqlite that stores the bookmarks and the history.

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox

Solution confirmed and reproduced.

I had a copy of "All bookmarks" in my bookmarks. Just deleted it to get all work properly.

Thank you all

Glad it worked out.