Hi,
Problem: one of the three monitors in Ubuntu is not recognized, even when that monitor can be used within the Ubuntu environment as a display.
Details: I was able to connect two external monitors to my MacBookPro11,3 using a DVI dongle and the HDMI output. All three monitors work fine on OS X 10.9.2. I have a virtual Ubuntu 12.04 running with VMWare Fusion 6.0.2. The three monitors are indeed correctly used by Ubuntu. The problem I have is that the third monitor it is used by Ubuntu as a display (so, you can move a window to that monitor and display it correctly), but the background is black (no desktop picture is shown in there) and the Display tool of Unity does not recognize it at all. So, only two monitors are shown in the Ubuntu Display tool panel (the retina display one and one of the external monitors). The implication of this is that I do can use the third monitor, but can't show the Unity bar (as in the other two monitors) and can't set a background picture.
I don't really know if the problem is Ubuntu, MBP, VMWare, or a combination of them.
Does anyone knows or has a hint on how to solve this problem?
Hernan