I also experience this problem. However, it is random and I don’t know exactly what my app does that triggers it. But sometimes when running my webapp launched from the homescreen in fullscreen, after a while, suddenly the home button stops responding. I seems to happen randomly but often enough that it will happen a few times a week if I am using the fullscreen webapp a lot. In iOS-7.0.4, I am still able to use the lock button. But when I go to unlock the iPad, the screen never wakes up and I’m pretty sure that means touch input is disabled. So I have to resort to an unclean reboot.
This bug has been around for quite a while and it is kind of disappointing that it can happen. If the fullscreen webapp functionality were used by inexperienced users, it would be quite baffling if the device suddenly fails to wake up. The device is, by all appearances, powered off, but the usual solution to that—pressing the power button to turn it on—does nothing.