I found an alternative way to get the resolution I wanted, what I did was use xrandr to create the new resolution I wanted, so even though it still says unknown display I have the option to select the correct resolution, and the screen looks perfect now.
In my case I needed the 1360x768 resolution (it only gave me the option for chosing 1024x768 or 800x600)
so here is how I got the right resolution:
Screen 0: minimum 8 x 8, current 1024 x 768, maximum 32767 x 32767
HDMI1 disconnected (normal left inverted right x axis y axis)
VGA1 connected primary 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
800x600 60.32 56.25
VGA1 is my device, then I created the resolution I wanted
alex@Minx:~$ sudo cvt 1360 768 60
# 1360x768 59.80 Hz (CVT) hsync: 47.72 kHz; pclk: 84.75 MHz
Modeline "1360x768_60.00" 84.75 1360 1432 1568 1776 768 771 781 798 -hsync +vsync
Created a new mode for my resolution:
alex@Minx:~$ xrandr --newmode "1360x768_60.00" 84.75 1360 1432 1568 1776 768 771 781 798 -hsync +vsync
Finally added the new mode to my VGA1 device:
alex@Minx:~$ sudo xrandr --addmode VGA1 1360x768_60.00
Then I went to Displays and was able to select the 1360x768 resolution.