there is a workaround where you
1) go to an apple stock application (e.g. Weather)
2) hold the power button until you see "Slide to power off". Let go of the power button
3) once you see this - press and hold the home button until the main screen is displayed again.
Apparently this reconfigures the sensitivity of the button.
It's quite clear that the problem can be software related and undoubtedly in some circumstances the Home Button can be damaged so as to need a "proper" repair, but these fixes have got to be worth trying...