My launch day iphone 4 had a dead home button, took it into the Apple store the next day and they replaced it with my current iphone 4. It's been doing great for a few months, but over the last few weeks the unresponsiveness of the home button has been steadily increasing. It sometimes seems impossible to get the app bar to come up (double-click) and instead it has a delayed response (like a 3G on ios 4) that brings me to the home screen, or search screen, depending on where the display is. It seems like a software issue as there are times when it works perfectly. That's why I'm posting this problem. Is anybody else having this issue? I suspect the last update might have screwed it up. I'll attempt a full restore this weekend and see if that works.