computer says Norton turned off even when it is on

Hi. I have Norton 2009, and recently there's been an icon in the lower righthand side of my screen telling me that Norton Internet Security is turned off, but I've repeatedly checked and it is turned on. I have also run the live update and run a full system scan. They all say that my system is up-to-date and secure. Why, then, does Windows say Norton is turned off and not running? What can I do to fix this problem and make sure that my computer is protected?