I have a dual-head setup running Ubuntu 13.04 with Gnome/Unity (the default desktop). What I'm trying to achieve is to display Firefox in "fullscreen" mode (e.g. hit F11 after it is launched), and have Firefox be displayed as a single window across both screens. I've dug every possible setting in Gnome and can't find out how to have fullscreen span across the whole desktop.
I have an nVidia video card with the latest driver (313.26) installed, and TwinView enabled. I tried messing with the "NoTwinViewXineramaInfo" option but to no avail.
Is what I'm trying to accomplish even possible on Gnome/Unity? If so, how must I configure the desktop to achieve it?