Lately my iPhone 4 has been acting strange. When I press the 'on' button (the one at the top) the iPhone sometimes does't react, and when I press it again it only flashes the unlock screen and goes back to black. Then, when I press it again everything is normal. Sometimes it doesn't do the black screen, but something else that is unusual is that the flash that comes on the 'unlock' word looks like it is fast forwarded at first and the goes back to being normal (I don't know how to explain this one). Also, when I unlock it (after I typed my pin) it has a black screen only for a short period of time (like half a second) and then it is normal again. That stuff all usually happens when the phone has been in "sleep" mode for a certain period of time. So when it behaved like this it won't do it again unless I let it "sleep" for like 15 or 20 minutes. I did do a reset yesterday and it is still exactly the same as it was before. It is already a phone that I got from the Apple Store as an exchange for a phone that had problems with the Home Button. What do you guys think I should do? Go to the Apple Store because of it? I just bought Apple Care for the phone, so it is under warranty.....Do you think it is a software issue? It seems like one to me, but with a software issue you don't get a new phone, as a replacement right? Any other ideas except for resetting it? Thanks for he help!