it may not be a driver or driver upgrade related problem,check if all the buttons are working properly,i bought a pc joystic(company name:gladiator) a year ago,it came along with a driver that creates vibration,but it's button 5 and 6 were not so responsive,i had to press them hard whenever i used it,it became a bit smoother few months later,yet i prefer not using those 2 buttons when i'm in a serious bossfight or something like it..