Simple proof of concept: http://jsfiddle.net/rVxkv/ http://jsfiddle.net/rVxkv/ This opens 2 Thunderbird windows in Firefox 26 but only one in Chromium 31.0.165

Simple proof of concept: http://jsfiddle.net/rVxkv/ http://jsfiddle.net/rVxkv/ This opens 2 Thunderbird windows in Firefox 26 but only one in Chromium 31.0.1650.63. edit: I totally agree it shouldn't be possible :)