I use a Genius tablet for Windows XP, and about a month ago the pen stopped tracking along the tablet. IDealy, the tablet tracks the pen when the pen is hovering about an inch above the surface, but now it will not detect the pen unless I click the pen button and hold it or press the pen to the tablet, both of which causing disruptions while I try to paint. I've changed both the nib and battery, yet nothing has changed. Has anyone had this problem? Can anyone help?