A possible cause is 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

There are other things that need your attention.

Your above posted system details show outdated plugin(s) with known security and stability risks that you should update.

1. Shockwave Flash 10.1 r102
2. Java Plug-in 1.6.0_11 for Netscape Navigator (DLL Helper)

Update the Flash plugin to the latest version.

• https://support.mozilla.com/kb/Managing+the+Flash+plugin
• http://kb.mozillazine.org/Flash
• http://www.adobe.com/software/flash/about/

Update the Java plugin to the latest version.

• https://support.mozilla.com/kb/Using+the+Java+plugin+with+Firefox
• http://kb.mozillazine.org/Java
• http://www.oracle.com/technetwork/java/javase/downloads/index.html (Java Platform: Download JRE)

Bookmarks gone after update

If you use Norton 360

• Configuring Norton 360 | How to | Firefox Help
  https://support.mozilla.com/kb/Configuring%20Norton%20360

See if you have your bookmarks by looking in the bookmarks sidebar (Ctrl+B) and expanding the folders.

If you have the correct bookmarks in the sidebar, maybe you are not displaying your bookmarks toolbar, "Alt+V" > Toolbars > (checkmark) Bookmarks Toolbar

• http://kb.mozillazine.org/Lost_bookmarks

If it is the default set of bookmarks and not your own perhaps you are using a new profile. Check updated dates of places.sqlite in each of your profiles, if you have multiple profiles -- do not open other profiles with the profile manager as that would change the datestamps.

• https://support.mozilla.com/en-US/kb/Lost%20Bookmarks#w_default-set-of-bookmarks-is-shown-in-bookmarks-folder

You can get to your other profiles by using Help > Troubleshooting Information... > "Open Containing Folder" > then go up on directory level and check each profile folder in the Profiles directory for dates on places.sqlite

If you find one then note its filename (the profile name is part of the filename) and then start the Firefox Profile Manager and open with that profile. The name you select when bringing up the profile manager becomes your default profile.

To prevent the problem in the future don't let Firefox start up for you after downloading and installing a new version. Instead exit the install at that last point, and restart Firefox in your normal manner.