Does the extension still give a sound on other events?

It is possible that the extension is broken due to changes in current Firefox releases.

There are other things that need your attention.

Please update to the current Firefox 23.0 release.

• Help > About Firefox

• https://support.mozilla.org/kb/update-firefox-latest-version.
• https://support.mozilla.org/kb/Updating+Firefox

The Firefox 19 version that you currently run is no longer supported with security updates.

• It is important to update Firefox and add-ons to the latest version to get all security fixes.

I didn't know there was an add-on for that! What's it called?

You probably know that Firefox recently updated to version 23. I don't know whether upgrading will improve the add-on's performance, but you should consider it for security reasons.

Version 21 is not secure; Mozilla discloses security flaws after each new release. Is something holding you back from upgrading to Firefox 23? Please let us know so we can suggest solutions or workarounds.

If Help > About Firefox shows Firefox 23.0, you may need to clear the preference that is misreporting your version number. See: How to reset the default user agent on Firefox.

• Navigational Sounds: https://addons.mozilla.org/firefox/addon/navigational-sounds/

hi , have installed firefox 23.0 and still have the same problem, the extension has 4 other sound events which still work

It seems that the extension plays the sounds set in the Windows Control Panel. Can you check there to make sure the Start Navigation sound is set? The attached screen shot is from Windows 7; I don't have Windows XP handy.