Can you open the right-click context menu of that bookmark to open the bookmark in a new tab?

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do not click the Reset button on the Safe mode start window or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

The situation is still the same in Safe Mode; middle-clicking on bookmarks in the bookmarks menu does nothing, instead of opening the bookmark in a new tab. I can still right-click and select open in a new tab, but that rather defeats the point of having middle click open in a new tab in the first case. It slows me down greatly.

Middle-clicking is working properly everywhere else on my computer, except in the Bookmarks Menu.

The issue is still the same in Firefox 16.0.1, with the added hurdle that 16.0.1 is not stable. Even in Safe Mode, with Hardware Acceleration turned off, Firefox is freezing up, sometimes for as long as 1 minute; no particular sites; sometimes it will for specific sites, sometimes not.

Again, going to Safe Mode has not solved either problem.

Try a clean reinstall and delete the Firefox program folder before reinstalling a fresh copy of Firefox.

• C:\Program Files\Mozilla Firefox\
• http://kb.mozillazine.org/Installation_directory

Download a fresh Firefox copy and save the file to the desktop.

• Firefox 16.0.x: http://www.mozilla.org/en-US/firefox/all.html

Uninstall your current Firefox version, if possible, to cleanup the Windows registry and settings in security software.

• Do NOT remove personal data when you uninstall your current Firefox version, because all profile folders will be removed and you will also lose your personal data like bookmarks and passwords from profiles of other Firefox versions.

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

• It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
• http://kb.mozillazine.org/Uninstalling_Firefox

Your bookmarks and other profile data are stored in the Firefox Profile Folder and won't be affected by an uninstall and (re)install, but make sure that "remove personal data" is NOT selected when you uninstall Firefox.

If you keep having problems then also create a new profile.

• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Profile_backup

• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Clean_reinstall

Reinstalling, and creating a new profile did nothing to fix the problem. Middle-clicking on items from the Bookmark Menu still does nothing, rather than opening the bookmark in a new tab.

Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.
Windows will use standard drivers in Safe mode.

Middle Click Tab Opening works properly in Safe Mode. But there's no rollback possible for the mouse driver and no driver available at the Logitech (mouse manufacturer) site.

Just to make a liar of me, I checked my device manager and today (unlike every previous time I've checked), the Mouse Driver Rollback button was active. Rolling back the mouse driver has resolved the problem. Thanks for the help.