I don't think that's a hardware issue, as this very rarely happened before but started to happen immediately and repeatedly following the iOS 8 update. So, when an app is open, pressing the home button doesn't send this app to the background, but launches the app switcher as if I had typed twice. That's really upsetting, I mean it keeps happening again and again.
iPhone 4S, iOS 8
Frustrating it certainly is, no hardware issue, chance of this happening on an ipad 3, ipad mini ret and iphone 5 just after ios 8 installation where none of these devices had this issue before is virtually none-existent.
Not sure if it would matter, but you can go into Settings>General>Accessibility and set the Home-click Speed. See if changing that makes a differenc.
Tried this, but as expected, it makes it worse... it's annoying, the only ios device not having this problem is my wives 4s. Feels stupid to work with the 'defragmentation' of ios when encountering these problems. Every other homeclick now shows the multitasking screen and the suddenly it does not for a while... Can't waite for Yosemite..
fixed with iOS 8.1
home button misbehaving in iOS 8
