How to fix dual monitor mode rotation problem in Ubuntu 12.x

It often happens when you are trying to connect additional monitor to your laptop via VGA port and all you see is only clockwise or anticlockwise rotation options in your Displays settings while all you need is to rotate the picture 90 degrees only.
In such case you need to manually configure your display setting from a terminal. All you need to solve this problem is to open the terminal window and type in the command:

xrandr --output VGA1 --mode 1440x900 --rotate normal

From example above you should use proper VGA port as an --output parameter. Use xrandr command in terminal to get the list of your video output ports and modes. You may also avoid specifying resolution manually by using --auto instead of --mode 1440x900.
For --rotate parameter you may use left or right value depending on your preferences.
Use man xrandr for more information ;)