So I've been using this iPhone 4 for a couple of months now and suddenly yesterday I've been noticing that the home button is not responsive like it used to be. Like 8 out of 10 times it works, but there's like once or twice it doesn't respond. Is this common with iPhone 4 after a while? Could it be software-based? Like it's been 2 weeks I haven't turned off my phone... Thanks for all responses.