Unknown display besides laptop Built-in display. Old question but with no answers [duplicate]

After my update from 12.04 to 13.10 my display configuration started showing an extra unknown monitor, even though I have nothing connected.

lscpi:

00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
01:00.0 VGA compatible controller: NVIDIA Corporation GF108M [GeForce GT 540M] (rev a1)

xrandr

Screen 0: minimum 320 x 200, current 1366 x 768, maximum 32767 x 32767
LVDS1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
   1366x768       60.0*+   60.1  
   1360x768       59.8     60.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
VGA1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
VGA-2 connected (normal left inverted right x axis y axis)
   1024x768       60.0  
   800x600        60.3     56.2  
   848x480        60.0  
   640x480        59.9  
  1024x768 (0x43)   65.0MHz
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  800x600 (0x44)   40.0MHz
        h: width   800 start  840 end  968 total 1056 skew    0 clock   37.9KHz
        v: height  600 start  601 end  605 total  628           clock   60.3Hz
  800x600 (0x45)   36.0MHz
        h: width   800 start  824 end  896 total 1024 skew    0 clock   35.2KHz
        v: height  600 start  601 end  603 total  625           clock   56.2Hz

This problem seems to had been previously asked here and here.

Any ideas on how to solve this?

I have finally found a working solution in these two questions: one, two

Basically one needs to edit sudo gedit /etc/default/grub and replace

GRUB_CMDLINE_LINUX=""

by

GRUB_CMDLINE_LINUX="video=VGA-2:d"

where VGA-2 is the name of the incorrectly connected display shown by xrandr.

Run

sudo update-grub

and reboot