Rated 1 out of 5 stars
Doesnt seem to work here, "No closed tabs to undo".
The tab-bar button placement seems counterintuitive IMO, it should be on the tabbar's right, it or at least its position being customizable.
Context menu of tabbar button its the same as tabs.
Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6 (.NET CLR 3.5.30729).