If you guys notice that one of your control buttons on your keyboard isnt functioning normally then I suggest the following test:
OPen Microsoft Word etc... and test the other buttons in that area and see if they show similar signs to other keys on the functioning side. Then prize them off and put the correct keys back in their normal slot.
Im just saying this because it happenned to someone very close to me. And Im grateful to have both control keys back now.
My defence is that I was cleaing my 5 yo keyboard and well. I thought they were the right slots. Only took me 4 months or so to notice I think.