Symbols shifted by one button

So i recently bought a Macbook Air 2012 model and since i bought it from another user so i made a format and a fresh install of OSX Mavericks. However i noticed that they keyboard symbols (printed on numbers) are shifted by one button.
Simply what i mean is that instead of pressing Shift(8) to open a bracket and shift(9) to close it, i have to press shift(9) to open a bracket and shift(0) to close it!
Here is a picture of my Mac keyboard and the corresponding symbols written when i press shift + buttons, starting from the left to right.
http://i.imgur.com/giZHTzX.jpg
http://i.imgur.com/K5fXmAE.jpgAnd here is again the buttons (upper row) and the corresponding shifted symbols (lower row).

§ 1 2 3 4 5 6 7 8 9 0 - =

± ! @ # $ % ^ & * ( ) _ +

i tried changing the input language to British and the US international or any other US format but still the problem exists. I think it might be caused by installing the OSX of a specified region on my mac which seems to be from another region.
Anyway to solve this?