Firefox 4 Settings - how to use tab groups, etc

Open Firefox 4.
Top Left Firefox Menu | Options | Uncheck "Tabs on Top".
Top Left Firefox Menu | Options | Check "Menu Bar".
Enable Tab Groups icon. Either
Click the down arrow located at the right end of Firefox Tab and then select Tab Groups or
press Ctrl+Shift+E.
Move an existing weblink to the empty space, a new tab group will be created.
Double click to open the newly created tab group.
Ctrl+T to open a new tab.
The Tab Groups icon is automatically come into view.
Click on "Group your tabs" icon.
Move back your existing weblink to your previous tab group.
Double click "New Tab" weblink on your second tab group.
And now, you have zero tab on your browser because all your old weblinks are hidden away inside the first tab group.