Switch to Tab no more: https://addons.mozilla.org/en-US/firefox/addon/switch-to-tab-no-more/

If you want to duplicate an existing open tab in Firefox 4, middle-click the combined Go/Reload/Stop icon at the right end of the URL/Location/Address Bar (middle-click = press the mouse scroll wheel).

You need to update the following out-of-date plugin:

• Adobe Shockwave for Director Netscape plug-in, version 11.5.9.615

1. Check your plugin versions on either of the following links':
   • http://www.mozilla.com/en-US/plugincheck/
   • https://www-trunk.stage.mozilla.com/en-US/plugincheck/
   • Note: plugin check page does not have information on all plugin versions
2. Update Shockwave for Director
   • NOTE: this is not the same as Shockwave Flash; this installs the Shockwave Player.
   • Use Firefox to download and SAVE the installer to your hard drive from the link in the article below (Desktop is a good place so you can find it).
   • When the download is complete, exit Firefox (File > Exit)
   • locate and double-click in the installer you just downloaded, let the install complete.
   • Restart Firefox and check your plugins again.
   • Download link and more information: http://support.mozilla.com/en-US/kb/Using+the+Shockwave+plugin+with+Firefox

I'm working on my laptop, so don't have a wheel on my mouse. I also don't see how I could simultaneously select my target from the drop-down list and middle click the right end of the Locator bar. Perhaps I am misunderstanding.

However, I have downloaded the plug in & it works!

Thanks.

When using a laptop, it is important to mention that fact in your question. Had I known the question pertained to a laptop, I would not have posted an answer. Sorry. Maybe someone else will come along with a suggestion.