I don't know if this question already was answered. When i has many windows opened (four or more) and between of hers there is one of CD-ROM, the mouse is stopping if i move do it fast (if i move do it slow , nothing happen). The mouse don't follow the trajectory and does halt flashed. If the number of windows is low and the window of CD-ROM don't exist, it run well. My mouse is GENIUS. Could it be to my mouse driver? Or is from beta 2.0?