not sure if you're facing this issue.
i recently bought a protective cover, and after fixing it, noticed that the device is behaving odly.
it sleeps intermittently during use (as if you pressed the on/off button) and when you press on/off to turn it back, the home button and capacitive buttons are not functional. Back, home, and the task buttons can't work... after a few minutes of on/off, then it's ok.
however, when i take it out of the protective cover, it doesn't happen.
any of you have that problem?