Mrs Redboots wrote:

Thanks, Dave - in fact, this was not recommended by the Mozilla
people, so I downloaded their recommended one instead:
http://tinyurl.com/5w4qu

JFYI, I maintain that extension. If you want additional tab features,
you should add the miniT, Click2Tab, FLST and Undo Close Tab
extensions. All these are more can be had from
http://www.extensionsmirror.nl/