Many assigned functions dont work as expected. e.g. horizontal scrolling dont work many times. I have assigned 'ctrl' function to middle button so that i can press and scroll to zoom-in. But it doesnt work at times. However, it starts working after some time.
Also, give some memory to the mouse so that all these settings can be stored within the mouse hardware itself. It'll help prevent such glitches, particularly on office computers where many apps are banned or prevented from executing actions.