Hey I think there is two possibility here,
It's either your mouse is factory defect or the touch pad is still on
If it is the first one, just go back and exchange one
if it's the second one just simply turn off your touch pad by
pressing Fn-f9, I realize if I have my mouse and my touch pad on
my hand will randomly rub on it and make my cursor vibrate around:p
Asus G74sx-A1
CPU: i7-2630QM
GPU: nVidia 560M 3GB
RAM: 12GB
Hard Drive: 1.5TB