Minecraft: Can't screenshot my coordinates?

So ever since minecraft 1.7 came out, I have not been able to screenshot my coordiantes or my inventory… I use to be able to but now I can't, and I know this is not a new feature cause other people can still do it… So is there a way to fix this so I can screenshot my cordinates and my inventory again? *Also I can take regular screenshots just not the ones of cordnates or inventory*