Three phantom monitors after upgrading to Mavericks I just upgraded my old Macbook Air (late 2010) from 10.6.8 to Mavericks 10.9.4. The OS now sees three ghost monitors that do not exist:



When I'm cordless, I can work around by mirroring the monitors, but I typically work with multiple monitors where mirroring is pointless.

I found a few references to this problem online (particularly here). I followed the directions from the first link (reset PRAM, detect displays, no joy). 
Additional information


The other monitors are all called "built-in display". 
Under the hardware system report (About This Mac-> More Info-> System Report -> Graphics Displays), I find only the LCD monitor attached to the Mac.
'Detect displays' still detects the same phantom displays.
An external monitor works, but I still see the three phantom monitors.


Questions
Are there any available solutions or workarounds? For example:


Can I use software to disable the extra monitors? 
The poster in the second link above got joy with graphicsenabler = YES options in Chameleon. Can I replicate that setting that in my situation?
I came up with a workaround when I was finalizing the question: mirror only the phantom displays. To do this, go to System Preferences-> Displays and click Arrange (click gather windows if you don't see an option to mirror displays). 

While holding the Option key, drag the windows that you wish to mirror on top of one another.  (In my case, I mirrored all of the phantom monitors on top of one another.) Release the option key and arrange the other monitors as you like.