Not sure if it matters, but I'm using apple's wall power adapter. I don't see them on the apple store anymore, so I'm guessing they've stopped producing it? It's the small square power adapter. Similar to MacBook power adapter just a smaller size. I was unplugging it after it has finished charging my iPad 2 and I noticed that it was really hot. Is this normal? I've charged my iPad using that charger numerous times, but this is the first time I've touched it after it has finished charging. I also use it for my iPhone and iPod, and it's fine (I think). Should I be concern about this?