User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13 ( .NET CLR 3.5.30729; .NET4.0E) Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13 ( .NET CLR 3.5.30729; .NET4.0E) There is a little tiny bar that runs underneath the tabs itself. Clicking this bar whether you have one or many tabs opens, anywhere along the bar creates new blank tabs. Reproducible: Always Steps to Reproduce: 1.Open Firefox 2.Open one or more tabs 3.Move mouse to the little Bar underneath the tabs. 4.Click Bar Actual Results: More blank tabs are created Expected Results: not do anything, this bar should be decorative purposes only (i presume) Using CTRL+T or the + button at the end of the tabbed browsing should be the only way to create new tabs.

That's a clear duplicate of a bug I'm not able to find at the moment.