Touch sensitive controls frozen. Cant use media or shut down!

Please can you help me. I have a Studio 1737 which has touch sensitive icons/controls above the keyboard for media access such as volume controls, eject button, play, stop ff etc. The problem i'm having is with the 'icon'/button with the clapperboard/media/music logo - the light will not go off and the whole of that top area is frozen. I have not been able to shut down the laptop properly as the light being on suggests to the laptop that the media services are being used.

Has anyone experienced this before and how can i unfreeze the light and the rest of the touch sensitive controls.