I have to get really close to the bamboo just for my pen to draw and there isnt enough space for me to roam, is this fixable?

I had had my bamboo tablet for about two or three years and my pen started going crazy and now i have to get real close to the tablet and there wouldn't be enough space to be able to roam around freely without having to go back down. Is this fixable or do I have to get another pen, if I do how do I know it is right for my tablet?