I recently downloaded the demo version of Vue and noticed something similar. What I saw was that there was sometimes a significant delay between when you started moving the mouse and when Vue caught up, but as long as you keep the mouse moving there is no delay. It is also intermittent (over a period of seconds), I can't get it to do this every time I pause the mouse movement. Of course I don't have an answer for you, but at least you know it probably isn't your mouse acting up.