Troubleshooting extensions and themes

• https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes

Sorting Bookmarks

• https://support.mozilla.com/en-US/kb/Sorting%20bookmarks

IF this still doe not work, see these:

Locked or Damaged places.sqlite

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

Corrupt localstore.rdf

• http://kb.mozillazine.org/Corrupt_localstore.rdf

Check and tell if its working.

Thanks, but I'd tried all these steps before posting my question.

Use this add-on - SortPlaces

• https://addons.mozilla.org/firefox/addon/sortplaces/

Check and tell if its working.

The add-on appears to have worked. I'm still puzzled by Firefox's behavior, and why it needs to be corrected by an add-on.

There are other things that need your attention.

Your above posted system details show multiple Java Console extensions.
You can uninstall and remove Java Console extensions, you do not need them to run Java applets.

See:

• http://kb.mozillazine.org/Java#Multiple_Java_Console_extensions

Disable the Java Quick Starter extension: Tools -> Add-ons -> Extensions

• Control Panel -> Java -> Advanced tab -> Miscellaneous -> Java Quick Starter (disable)

See:

• http://www.java.com/en/download/help/quickstarter.xml - What is Java Quick Starter (JQS)? What is the benefit of running JQS? - 6.0

You may also want to reset some excessive connection settings (about:config) that show in your More system details list. Website Administrators usually do not like such tweaks.

network.http.max-persistent-connections-per-server 102
network.http.pipelining.maxrequests 30