Could happen with the dirt and what not.
Although in this case, there is a distinct character that is typed when the Ctrl key is held and a letter is pressed. Which means that either the Ctrl key is a bit on the bjorked side, or that the Fn key or Num Lock is active (since this is a laptop and all), and the extra functions are being used. Which happens quite often on the one small field laptop by us - the guys often press the Num Lock key by mistake, which toggles on number functions instead of letters. So then when they press the 'p' key for example, they get a '*' as the 'p' key also functions as the multiply key that would appear on the num-pad of a full sized keyboard. And then on another of our site laptops, the same functionality is enabled by pressing the Fn key...