If you are using OpenGL and you do not have the latest Logitech drivers, then you could have problems. They added a feature related to game play, and for several revs of the driver there was no way to disable it - which you needed to do for any OpenGL app! My driver is 9.97, but different mouse, so number may vary. But you are looking for "Disable acceration in games", on the Motion panel in mine, and you want to UNcheck it.