To reproduce this: run XFCE, put Firefox on the left monitor (or maybe centre for triplehead), maximise firefox window, then right click on the right side of the Firefox window. The popup will appear on the monitor to the right. Tested with Debian Testing and Firefox 29 beta (and Iceweasel).
To reproduce this: run XFCE, put Firefox on the left monitor (or maybe centre for triplehead), maximise firefox window, then right click on the right side of the Firefox window. The popup will appear on the monitor to the right. Tested with Debian Testing and Firefox 29 beta (and Iceweasel).