Hold down the Ctrl key while dragging the tab with your left mouse button, release mouse button when you see an arrow pointing between tabs. The same tab, with its history, will be duplicated on the tab bar. See (Tabs and Windows > Copy Tab): http://www.7is7.com/software/firefox/shortcuts.html

Extensions that give you additional tab functions/settings, including right-click Duplicate Tab function:

• Tabberwocky (light-weight extension): https://addons.mozilla.org/en-US/firefox/addon/14439/
• Tab Mix Plus (more extensive): https://addons.mozilla.org/en-US/firefox/addon/1122/

The information submitted with your question indicates that you have out of date plugins with known security issues that should be updated. To see the plugins submitted with your question, click "More system details..." to the right of your original question post.

• Adobe PDF Plug-In For Firefox and Netscape
• Next Generation Java Plug-in 1.6.0_14 for Mozilla browsers

1. Check your plugin versions: http://www.mozilla.com/en-US/plugincheck/
   • Note: plugin check page does not have information on all plugin versions
2. Update Adobe Reader (PDF plugin):
   • From within your existing Adobe Reader (if you have it already installed):
     • Open the Adobe Reader program from your Programs list
     • Click Help > Check for Updates
     • Follow the prompts for updating
     • If this method works for you, skip the "Download complete installer" section below and proceed to "After the installation" below
   • Download complete installer (if you do NOT have Adobe Reader installed):
     • Use Firefox to download and SAVE the installer to your hard drive from the link in the article below
     • On the Adobe page, un-check any extra items (i.e. Free McAfee® Security Scan Plus) then click Download button
     • If you see message just under tabs, DO NOT click the Allow button, instead click below that where it says "click here to download".
     • Click "Save to File"; save to your Desktop (so you can find it)
     • After download completes, close Firefox
     • Click the installer you just downloaded and allow the install to continue
       • Note: Vista and Win7 users may need to right-click the installer and choose "Run as Administrator"
     • Download link and more information: https://support.mozilla.com/en-US/kb/Using+the+Adobe+Reader+plugin+with+Firefox#Installing_and_updating_Adobe_Reader
   • After the installation, start Firefox and check your version again.
3. Update Java:
   • Download and update instructions: https://support.mozilla.com/en-US/kb/Using+the+Java+plugin+with+Firefox
   • Removing old versions (if needed): http://www.java.com/en/download/faq/remove_olderversions.xml
   • Remove multiple Java Console extensions (if needed): http://kb.mozillazine.org/Java#Multiple_Java_Console_extensions
   • After the installation, start Firefox and check your version again.

You can also:

• Ctrl-click or middle-click the Reload button to open the current page in a new tab (no tab history).
• Ctrl-click or middle-click items in the history of the Back and Forward buttons to open a page from that list in a new tab.
• Duplicate a tab with its history by pressing CTRL and dragging the tab to a new position on the tab bar.
• Dragging a tab in the browser window will detach the tab and move it to a new window, this is called tab tearing.
• Drag a tab back to the tab bar in the original or anther window to undo a detach or move a tab to a specific window. If a window gets empty (you tear off the last tab) then that window will be closed automatically.