iPad 2 Home Button unresponsive

Occasionally, I press the Home Button, the iPad 2 will do nothing. Ppressing it again, sometimes upwards of 4 or 5 presses before it finally responds. Each press is an appropriate amount of force and I doesn't mash the button.I close all running apps and restart the iPad 2, the Home button is perfectly responsive for 3 hours. And I will get the non-responsive Home button again. After restoring to